Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-nspire/mmio.h b/arch/arm/mach-nspire/mmio.h
index 8813471..48e32f1 100644
--- a/arch/arm/mach-nspire/mmio.h
+++ b/arch/arm/mach-nspire/mmio.h
@@ -1,12 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *	linux/arch/arm/mach-nspire/mmio.h
  *
  *	Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
- *
- * 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.
- *
  */
 
 #define NSPIRE_MISC_PHYS_BASE		0x900A0000