net: hns3: fix port info query issue for copper port

In original codes, for copper port which doesn't connect to phy,
it always returns -EOPNOTSUPP when query port information. This
patch fixes it by return the port information of MAC.

Fixes: 5f373b15 ("net: hns3: Fix speed/duplex information loss problem when executing ethtool ethx cmd of VF")
Signed-off-by: Jian Shen <shenjian15@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>