Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/thermal/tmon/Makefile b/tools/thermal/tmon/Makefile
index 735a510..59e417e 100644
--- a/tools/thermal/tmon/Makefile
+++ b/tools/thermal/tmon/Makefile
@@ -6,13 +6,13 @@
 
 BINDIR=usr/bin
 WARNFLAGS=-Wall -Wshadow -W -Wformat -Wimplicit-function-declaration -Wimplicit-int
-CFLAGS+= -O1 ${WARNFLAGS}
+override CFLAGS+= $(call cc-option,-O3,-O1) ${WARNFLAGS}
 # Add "-fstack-protector" only if toolchain supports it.
-CFLAGS+= $(call cc-option,-fstack-protector)
+override CFLAGS+= $(call cc-option,-fstack-protector-strong)
 CC?= $(CROSS_COMPILE)gcc
 PKG_CONFIG?= pkg-config
 
-CFLAGS+=-D VERSION=\"$(VERSION)\"
+override CFLAGS+=-D VERSION=\"$(VERSION)\"
 LDFLAGS+=
 TARGET=tmon
 
@@ -29,7 +29,7 @@
 		     $(PKG_CONFIG) --libs $(STATIC) panel ncurses 2> /dev/null || \
 		     echo -lpanel -lncurses)
 
-CFLAGS    += $(shell $(PKG_CONFIG) --cflags $(STATIC) panelw ncursesw 2> /dev/null || \
+override CFLAGS += $(shell $(PKG_CONFIG) --cflags $(STATIC) panelw ncursesw 2> /dev/null || \
 		     $(PKG_CONFIG) --cflags $(STATIC) panel ncurses 2> /dev/null)
 
 OBJS = tmon.o tui.o sysfs.o pid.o
diff --git a/tools/thermal/tmon/pid.c b/tools/thermal/tmon/pid.c
index fd7e9e9..c54edb4 100644
--- a/tools/thermal/tmon/pid.c
+++ b/tools/thermal/tmon/pid.c
@@ -1,21 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * pid.c PID controller for testing cooling devices
  *
- *
- *
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 or later as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * Author Name Jacob Pan <jacob.jun.pan@linux.intel.com>
- *
  */
 
 #include <unistd.h>
diff --git a/tools/thermal/tmon/sysfs.c b/tools/thermal/tmon/sysfs.c
index 18f5235..b00b1bf 100644
--- a/tools/thermal/tmon/sysfs.c
+++ b/tools/thermal/tmon/sysfs.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * sysfs.c sysfs ABI access functions for TMON program
  *
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 or later as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * Author: Jacob Pan <jacob.jun.pan@linux.intel.com>
- *
  */
 #include <unistd.h>
 #include <stdio.h>
diff --git a/tools/thermal/tmon/tmon.c b/tools/thermal/tmon/tmon.c
index b43138f..83ec6e4 100644
--- a/tools/thermal/tmon/tmon.c
+++ b/tools/thermal/tmon/tmon.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * tmon.c Thermal Monitor (TMON) main function and entry point
  *
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 or later as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * Author: Jacob Pan <jacob.jun.pan@linux.intel.com>
- *
  */
 
 #include <getopt.h>
diff --git a/tools/thermal/tmon/tmon.h b/tools/thermal/tmon/tmon.h
index 9e3c49c..c9066ec 100644
--- a/tools/thermal/tmon/tmon.h
+++ b/tools/thermal/tmon/tmon.h
@@ -1,19 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * tmon.h contains data structures and constants used by TMON
  *
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 or later as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * Author Name Jacob Pan <jacob.jun.pan@linux.intel.com>
- *
  */
 
 #ifndef TMON_H
diff --git a/tools/thermal/tmon/tui.c b/tools/thermal/tmon/tui.c
index b5d1c6b..031b258 100644
--- a/tools/thermal/tmon/tui.c
+++ b/tools/thermal/tmon/tui.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * tui.c ncurses text user interface for TMON program
  *
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 or later as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * Author: Jacob Pan <jacob.jun.pan@linux.intel.com>
- *
  */
 
 #include <unistd.h>