Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/wireless/lib80211.c b/net/wireless/lib80211.c
index 801d478..cc7b9fd 100644
--- a/net/wireless/lib80211.c
+++ b/net/wireless/lib80211.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * lib80211 -- common bits for IEEE802.11 drivers
  *