net: stmmac: Fallback to dev_fwnode() if needed

When CONFIG_OF is not enabled, of_fwnode_handle() will return NULL, even
though we can have a FW handle from a given device.

Fallback to dev_fwnode() helper if needed.
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -1043,6 +1043,9 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
 	priv->phylink_config.dev = &priv->dev->dev;
 	priv->phylink_config.type = PHYLINK_NETDEV;
 
+	if (!fwnode)
+		fwnode = dev_fwnode(priv->device);
+
 	phylink = phylink_create(&priv->phylink_config, fwnode,
 				 mode, &stmmac_phylink_mac_ops);
 	if (IS_ERR(phylink))