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/bfin_mac.c b/drivers/net/bfin_mac.c
index 26b2dd5..717dcc1 100644
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -969,7 +969,7 @@
 	lp->mii_bus.write = mdiobus_write;
 	lp->mii_bus.reset = mdiobus_reset;
 	lp->mii_bus.name = "bfin_mac_mdio";
-	lp->mii_bus.id = 0;
+	snprintf(lp->mii_bus.id, MII_BUS_ID_SIZE, "0");
 	lp->mii_bus.irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
 	for (i = 0; i < PHY_MAX_ADDR; ++i)
 		lp->mii_bus.irq[i] = PHY_POLL;