Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/hyperv/Makefile b/drivers/net/hyperv/Makefile
index 3f25b9c..3a2aa07 100644
--- a/drivers/net/hyperv/Makefile
+++ b/drivers/net/hyperv/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_HYPERV_NET) += hv_netvsc.o
 
 hv_netvsc-y := netvsc_drv.o netvsc.o rndis_filter.o netvsc_trace.o