net: hns3: add support for set_link_ksettings

This patch adds set_link_ksettings support for ethtool cmd.

Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>