net: vlan: announce STAG offload capability in some drivers

- macvlan: propagate STAG filtering capabilities from underlying device
- ifb: announce STAG tagging support in addition to CTAG tagging support
- veth: announce STAG tagging/stripping support in addition to CTAG support

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 7347cdb..d5a141c 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -471,7 +471,7 @@
 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
 	 NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO | NETIF_F_RXCSUM | \
-	 NETIF_F_HW_VLAN_CTAG_FILTER)
+	 NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_VLAN_STAG_FILTER)
 
 #define MACVLAN_STATE_MASK \
 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))