phylib: move to dynamic allocation of struct mii_bus

This patch introduces mdiobus_alloc() and mdiobus_free(), and
makes all mdio bus drivers use these functions to allocate their
struct mii_bus'es dynamically.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Andy Fleming <afleming@freescale.com>
diff --git a/drivers/net/bfin_mac.h b/drivers/net/bfin_mac.h
index beff510..052b5dc 100644
--- a/drivers/net/bfin_mac.h
+++ b/drivers/net/bfin_mac.h
@@ -66,7 +66,7 @@
 	int old_duplex;
 
 	struct phy_device *phydev;
-	struct mii_bus mii_bus;
+	struct mii_bus *mii_bus;
 };
 
 extern void bfin_get_ether_addr(char *addr);