Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index d02f818..a76f8ac 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * arch/arm/mm/highmem.c -- ARM highmem support
  *
  * Author:	Nicolas Pitre
  * Created:	september 8, 2008
  * Copyright:	Marvell Semiconductors 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 <linux/module.h>