net: ethernet: Add helper for MACs which support asym pause

Rather than have the MAC drivers manipulate phydev members to indicate
they support Asym Pause, add a helper function.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/sb1250-mac.c b/drivers/net/ethernet/broadcom/sb1250-mac.c
index 4ce4b09..53acbbb 100644
--- a/drivers/net/ethernet/broadcom/sb1250-mac.c
+++ b/drivers/net/ethernet/broadcom/sb1250-mac.c
@@ -2358,13 +2358,10 @@ static int sbmac_mii_probe(struct net_device *dev)
 
 	/* Remove any features not supported by the controller */
 	phy_set_max_speed(phy_dev, SPEED_1000);
-	phy_dev->supported |= SUPPORTED_Pause |
-			      SUPPORTED_Asym_Pause;
+	phy_support_asym_pause(phy_dev);
 
 	phy_attached_info(phy_dev);
 
-	phy_dev->advertising = phy_dev->supported;
-
 	sc->phy_dev = phy_dev;
 
 	return 0;