net: dsa: qca8k: use mdio_module_driver to simplify the code

mdio_module_driver() makes the code simpler by eliminating
boilerplate code.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed