Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 43a3ce2..d488311 100644
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Architecture specific (PPC64) functions for kexec based crash dumps.
  *
  * Copyright (C) 2005, IBM Corp.
  *
  * Created by: Haren Myneni
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
- *
  */
 
 #include <linux/kernel.h>