phy: Change mii_bus id field to a string

Having the id field be an int was making more complex bus topologies
excessively difficult.  For now, just convert it to a string, and
change all instances of "bus->id = val" to
snprintf(id, MII_BUS_ID_LEN, "%x", val).

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
index 0ee4c16..29a4d65 100644
--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -3954,7 +3954,7 @@
 		if (err)
 			return -1;
 
-		ug_info->mdio_bus = res.start;
+		snprintf(ug_info->mdio_bus, MII_BUS_ID_SIZE, "%x", res.start);
 	}
 
 	/* get the phy interface type, or default to MII */