Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/kernel/mips_machine.c b/arch/mips/kernel/mips_machine.c
index 8760975..4c50964 100644
--- a/arch/mips/kernel/mips_machine.c
+++ b/arch/mips/kernel/mips_machine.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
- *
- *  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.
- *
  */
 #include <linux/mm.h>
 #include <linux/string.h>