Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arc/mm/Makefile b/arch/arc/mm/Makefile
index 3703a49..633a773 100644
--- a/arch/arc/mm/Makefile
+++ b/arch/arc/mm/Makefile
@@ -1,10 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 #
-# 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.
-#
 
 obj-y	:= extable.o ioremap.o dma.o fault.o init.o
 obj-y	+= tlb.o tlbex.o cache.o mmap.o