net: hns3: After setting the loopback, add the status of getting MAC

After setting the serdes loopback, you need to determine
the status of the MAC negotiation. If a status exception
is obtained after 200ms, a timeout error is returned.

Signed-off-by: liuzhongzhu <liuzhongzhu@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>