Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/boot/ep405.c b/arch/powerpc/boot/ep405.c
index 2d08a86..f9ad1e6 100644
--- a/arch/powerpc/boot/ep405.c
+++ b/arch/powerpc/boot/ep405.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Embedded Planet EP405 with PlanetCore firmware
  *
@@ -8,10 +9,6 @@
  * 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 "ops.h"