Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/boot/stdlib.c b/arch/powerpc/boot/stdlib.c
index e00d58c..868b019 100644
--- a/arch/powerpc/boot/stdlib.c
+++ b/arch/powerpc/boot/stdlib.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * stdlib functions
  *
  * Author: Scott Wood <scottwood@freescale.com>
  *
  * Copyright (c) 2007 Freescale Semiconductor, Inc.
- *
- * 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 "stdlib.h"