gtp: add genl family modules alias

Auto-load the module when userspace asks for the gtp netlink
family.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
Acked-by: Harald Welte <laforge@netfilter.org>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 8b6810b..7580ccc 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1376,3 +1376,4 @@
 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
 MODULE_ALIAS_RTNL_LINK("gtp");
+MODULE_ALIAS_GENL_FAMILY("gtp");