Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/kernel/pm.c b/arch/mips/kernel/pm.c
index dc81489..486ed2b 100644
--- a/arch/mips/kernel/pm.c
+++ b/arch/mips/kernel/pm.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2014 Imagination Technologies Ltd.
  *
- * This program is free software; you can redistribute	it and/or modify it
- * under  the terms of	the GNU General	 Public License as published by the
- * Free Software Foundation;  either version 2 of the  License, or (at your
- * option) any later version.
- *
  * CPU PM notifiers for saving/restoring general CPU state.
  */