Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/sysdev/of_rtc.c b/arch/powerpc/sysdev/of_rtc.c
index 153fdac..1f408d3 100644
--- a/arch/powerpc/sysdev/of_rtc.c
+++ b/arch/powerpc/sysdev/of_rtc.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Instantiate mmio-mapped RTC chips based on device tree information
  *
  * Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
- *
- * 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.
  */
 #include <linux/kernel.h>
 #include <linux/of.h>