net: stmmac: ensure phydev is attached to phylink for C37 AN

As the support for MAC-side SGMII C37 AN is added to pcs-xpcs, phydev
should be attached to phylink during driver's open(). So, we change the
condition to "Not C73 AN" instead.
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -2898,7 +2898,7 @@ static int stmmac_open(struct net_device *dev)
 
 	if (priv->hw->pcs != STMMAC_PCS_TBI &&
 	    priv->hw->pcs != STMMAC_PCS_RTBI &&
-	    priv->hw->xpcs == NULL) {
+	    priv->hw->xpcs_args.an_mode != DW_AN_C73) {
 		ret = stmmac_init_phy(dev);
 		if (ret) {
 			netdev_err(priv->dev,