Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/media/uapi/v4l/pipeline.dot b/Documentation/media/uapi/v4l/pipeline.dot
index 02d7fcf..8c53ce7 100644
--- a/Documentation/media/uapi/v4l/pipeline.dot
+++ b/Documentation/media/uapi/v4l/pipeline.dot
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
 digraph board {
 	rankdir=TB
 	colorscheme=x11