Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/loongson64/common/irq.c b/arch/mips/loongson64/common/irq.c
index d36d969..0ea93c1 100644
--- a/arch/mips/loongson64/common/irq.c
+++ b/arch/mips/loongson64/common/irq.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2007 Lemote Inc. & Institute of Computing Technology
  * Author: Fuxin Zhang, zhangfx@lemote.com
- *
- *  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/delay.h>
 #include <linux/interrupt.h>