Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig
index e4242c3..f82a495 100644
--- a/fs/dlm/Kconfig
+++ b/fs/dlm/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 menuconfig DLM
 	tristate "Distributed Lock Manager (DLM)"
 	depends on INET