cxgb4: Enable outer UDP checksum offload for T6

T6 adapters support outer UDP checksum offload for
encapsulated packets, hence enabling netdev feature flag
NETIF_F_GSO_UDP_TUNNEL_CSUM.

Signed-off-by: Arjun Vynipadath <arjun@chelsio.com>
Signed-off-by: Vishal Kulkarni <vishal@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 200b160..1754ff7 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -5719,9 +5719,11 @@
 						   NETIF_F_IPV6_CSUM |
 						   NETIF_F_RXCSUM |
 						   NETIF_F_GSO_UDP_TUNNEL |
+						   NETIF_F_GSO_UDP_TUNNEL_CSUM |
 						   NETIF_F_TSO | NETIF_F_TSO6;
 
 			netdev->hw_features |= NETIF_F_GSO_UDP_TUNNEL |
+					       NETIF_F_GSO_UDP_TUNNEL_CSUM |
 					       NETIF_F_HW_TLS_RECORD;
 		}