Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/c6x/lib/csum_64plus.S b/arch/c6x/lib/csum_64plus.S
index 6d25896..8e625a3 100644
--- a/arch/c6x/lib/csum_64plus.S
+++ b/arch/c6x/lib/csum_64plus.S
@@ -1,3 +1,4 @@
+; SPDX-License-Identifier: GPL-2.0-only
 ;
 ;  linux/arch/c6x/lib/csum_64plus.s
 ;
@@ -6,10 +7,6 @@
 ;  Copyright (C) 2006, 2009, 2010, 2011 Texas Instruments Incorporated
 ;  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.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/linkage.h>
 
 ;