phy/bitbang: missing MODULE_LICENSE

Missing MODULE_LICENSE(), loading this module taints the kernel.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/phy/mdio-bitbang.c

@@ -185,3 +185,5 @@ void free_mdio_bitbang(struct mii_bus *bus)
 	module_put(ctrl->ops->owner);
 	kfree(bus);
 }
+
+MODULE_LICENSE("GPL");