pxa168_eth: fix a mdiobus leak

mdiobus resources must be released on exit
Signed-off-by: NDenis Kirjanov <dkirjanov@kernel.org>
Acked-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/pxa168_eth.c

@@ -1606,6 +1606,8 @@ static int pxa168_eth_remove(struct platform_device *pdev)
 
 	iounmap(pep->base);
 	pep->base = NULL;
+	mdiobus_unregister(pep->smi_bus);
+	mdiobus_free(pep->smi_bus);
 	unregister_netdev(dev);
 	flush_scheduled_work();
 	free_netdev(dev);