Fix missing exports for net/phy/mdio-bitbang.c

{alloc,free}_mdio_bitbang() are not exported while they are used in
mdio-ofgpio driver.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/net/phy/mdio-bitbang.c

@@ -177,6 +177,7 @@ struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl)
 
 	return bus;
 }
+EXPORT_SYMBOL(alloc_mdio_bitbang);
 
 void free_mdio_bitbang(struct mii_bus *bus)
 {
@@ -185,5 +186,6 @@ void free_mdio_bitbang(struct mii_bus *bus)
 	module_put(ctrl->ops->owner);
 	kfree(bus);
 }
+EXPORT_SYMBOL(free_mdio_bitbang);
 
 MODULE_LICENSE("GPL");