Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/raid6/avx512.c b/lib/raid6/avx512.c
index 46df797..bb684d1 100644
--- a/lib/raid6/avx512.c
+++ b/lib/raid6/avx512.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* -*- linux-c -*- --------------------------------------------------------
  *
  *   Copyright (C) 2016 Intel Corporation
@@ -8,12 +9,6 @@
  *   Based on avx2.c: Copyright 2012 Yuanhan Liu All Rights Reserved
  *   Based on sse2.c: Copyright 2002 H. Peter Anvin - All Rights Reserved
  *
- *   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, Inc., 53 Temple Place Ste 330,
- *   Boston MA 02111-1307, USA; either version 2 of the License, or
- *   (at your option) any later version; incorporated herein by reference.
- *
  * -----------------------------------------------------------------------
  */