ucc_geth: fix section mismatch

This fix section mismatch:
reference to .exit.text:uec_mdio_exit (between 'ucc_geth_init' and 'uec_mdio_init')

void __exit uec_mdio_exit(void) is called from
- static int __init ucc_geth_init(void)
- static void __exit ucc_geth_exit(void)

First one would make error path more than just an error.
Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: Li Yang <leoli@freescale.com>

drivers/net/ucc_geth_mii.c

@@ -272,7 +272,8 @@ int __init uec_mdio_init(void)
 	return of_register_platform_driver(&uec_mdio_driver);
 }
 
-void __exit uec_mdio_exit(void)
+/* called from __init ucc_geth_init, therefore can not be __exit */
+void uec_mdio_exit(void)
 {
 	of_unregister_platform_driver(&uec_mdio_driver);
 }