phy: Add an mdio_device structure

Not all devices attached to an MDIO bus are phys. So add an
mdio_device structure to represent the generic parts of an mdio
device, and place this structure into the phy_device.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/altera/altera_tse_main.c b/drivers/net/ethernet/altera/altera_tse_main.c
index 10d51e8..17472851 100644
--- a/drivers/net/ethernet/altera/altera_tse_main.c
+++ b/drivers/net/ethernet/altera/altera_tse_main.c
@@ -844,7 +844,7 @@
 	}
 
 	netdev_dbg(dev, "attached to PHY %d UID 0x%08x Link = %d\n",
-		   phydev->addr, phydev->phy_id, phydev->link);
+		   phydev->mdio.addr, phydev->phy_id, phydev->link);
 
 	priv->phydev = phydev;
 	return 0;