Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/misc/dummy-irq.c b/drivers/misc/dummy-irq.c
index 76a1015..fe3bfcb 100644
--- a/drivers/misc/dummy-irq.c
+++ b/drivers/misc/dummy-irq.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Dummy IRQ handler driver.
  *
@@ -10,11 +11,6 @@
  * Copyright (C) 2013 Jiri Kosina
  */
 
-/*
- * 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>
 #include <linux/irq.h>
 #include <linux/interrupt.h>