net/mlx4_en: Enable DCB ETS ops only when supported by the firmware

Enable the DCB ETS ops only when supported by the firmware. For older firmware/cards
which don't support ETS, advertize only PFC DCB ops.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index f710b7c..d4cb5d3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -624,6 +624,7 @@
 
 #ifdef CONFIG_MLX4_EN_DCB
 extern const struct dcbnl_rtnl_ops mlx4_en_dcbnl_ops;
+extern const struct dcbnl_rtnl_ops mlx4_en_dcbnl_pfc_ops;
 #endif
 
 int mlx4_en_setup_tc(struct net_device *dev, u8 up);