Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/strparser/Makefile b/net/strparser/Makefile
index 858a126..9313191 100644
--- a/net/strparser/Makefile
+++ b/net/strparser/Makefile
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_STREAM_PARSER) += strparser.o