Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/serial_max3100.h b/include/linux/serial_max3100.h
index 4976bef..befd55c 100644
--- a/include/linux/serial_max3100.h
+++ b/include/linux/serial_max3100.h
@@ -1,11 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  *
  *  Copyright (C) 2007 Christian Pellegrin
- *
- * 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.
  */