Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/nios2/lib/Makefile b/arch/nios2/lib/Makefile
index 5572566..9d5bf1d 100644
--- a/arch/nios2/lib/Makefile
+++ b/arch/nios2/lib/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for Nios2-specific library files.
 #
diff --git a/arch/nios2/lib/delay.c b/arch/nios2/lib/delay.c
index 088119c..f1e39c7 100644
--- a/arch/nios2/lib/delay.c
+++ b/arch/nios2/lib/delay.c
@@ -1,17 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright Altera Corporation (C) 2014. 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,
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
  */
 
 #include <linux/module.h>