Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/c6x/platforms/timer64.c b/arch/c6x/platforms/timer64.c
index 241a9a6..d98d943 100644
--- a/arch/c6x/platforms/timer64.c
+++ b/arch/c6x/platforms/timer64.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2010, 2011 Texas Instruments Incorporated
  *  Contributed by: Mark Salter (msalter@redhat.com)
- *
- *  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/clockchips.h>