Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/sound/pci/oxygen/xonar_lib.c b/sound/pci/oxygen/xonar_lib.c
index 706b1a4..e951f54 100644
--- a/sound/pci/oxygen/xonar_lib.c
+++ b/sound/pci/oxygen/xonar_lib.c
@@ -1,19 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * helper functions for Asus Xonar cards
  *
  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
- *
- *
- *  This driver is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License, version 2.
- *
- *  This driver 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.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this driver; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <linux/delay.h>