Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/media/dvb-drivers/technisat.rst b/Documentation/media/dvb-drivers/technisat.rst
index f80f4ec..9eaa123 100644
--- a/Documentation/media/dvb-drivers/technisat.rst
+++ b/Documentation/media/dvb-drivers/technisat.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 How to set up the Technisat/B2C2 Flexcop devices
 ================================================