Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index 82ba110..b132ab9 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * IPv4 over IEEE 1394, per RFC 2734
  * IPv6 over IEEE 1394, per RFC 3146