Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/media/dvb-drivers/udev.rst b/Documentation/media/dvb-drivers/udev.rst
index 7d7d5d8..ca6c9c2 100644
--- a/Documentation/media/dvb-drivers/udev.rst
+++ b/Documentation/media/dvb-drivers/udev.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 UDEV rules for DVB
 ==================