net: hns3: Support "ethtool -d" for HNS3 VF driver

This patch adds "ethtool -d" support for HNS3 VF Driver.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>