Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/perf/scripts/perl/rwtop.pl b/tools/perf/scripts/perl/rwtop.pl
index 8b20787..6473442 100644
--- a/tools/perf/scripts/perl/rwtop.pl
+++ b/tools/perf/scripts/perl/rwtop.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/perl -w
+# SPDX-License-Identifier: GPL-2.0-only
 # (c) 2010, Tom Zanussi <tzanussi@gmail.com>
-# Licensed under the terms of the GNU GPL License version 2
 
 # read/write top
 #