Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/xen/xen-stub.c b/drivers/xen/xen-stub.c
index bbef194..3be4e74 100644
--- a/drivers/xen/xen-stub.c
+++ b/drivers/xen/xen-stub.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * xen-stub.c - stub drivers to reserve space for Xen
  *
@@ -7,17 +8,6 @@
  *
  * Copyright (C) 2012 Oracle Inc
  *    Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.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.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT.  See the GNU General Public License for more
- * details.
  */
 
 #include <linux/kernel.h>