Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/boot/stdint.h b/arch/powerpc/boot/stdint.h
index c1c853b..5cc5e87 100644
--- a/arch/powerpc/boot/stdint.h
+++ b/arch/powerpc/boot/stdint.h
@@ -1,11 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * Copyright (C) IBM Corporation 2016.
  *
- * 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.
- *
  * This file is only necessary because some of the pre-boot decompressors
  * expect stdint.h to be available.
  */