net: vlan: Use the PHY time stamping interface.

The vlan layer tests fields of the phy_device in order to determine
whether to invoke the PHY's tsinfo ethtool callback.  This patch
replaces the open coded logic with an invocation of the proper
methods.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan_dev.c

@@ -646,8 +646,8 @@ static int vlan_ethtool_get_ts_info(struct net_device *dev,
 	const struct ethtool_ops *ops = vlan->real_dev->ethtool_ops;
 	struct phy_device *phydev = vlan->real_dev->phydev;
 
-	if (phydev && phydev->drv && phydev->drv->ts_info) {
-		 return phydev->drv->ts_info(phydev, info);
+	if (phy_has_tsinfo(phydev)) {
+		return phy_ts_info(phydev, info);
 	} else if (ops->get_ts_info) {
 		return ops->get_ts_info(vlan->real_dev, info);
 	} else {