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/freescale/ucc_geth.c b/drivers/net/ethernet/freescale/ucc_geth.c
index 650f788..0e7f24e 100644
--- a/drivers/net/ethernet/freescale/ucc_geth.c
+++ b/drivers/net/ethernet/freescale/ucc_geth.c
@@ -1385,7 +1385,7 @@
 		value &= ~0x1000;	/* Turn off autonegotiation */
 		phy_write(tbiphy, ENET_TBI_MII_CR, value);
 
-		put_device(&tbiphy->dev);
+		put_device(&tbiphy->mdio.dev);
 	}
 
 	init_check_frame_length_mode(ug_info->lengthCheckRx, &ug_regs->maccfg2);
@@ -1705,7 +1705,7 @@
 	 * several seconds for it to come back.
 	 */
 	if (phy_read(tbiphy, ENET_TBI_MII_SR) & TBISR_LSTATUS) {
-		put_device(&tbiphy->dev);
+		put_device(&tbiphy->mdio.dev);
 		return;
 	}