net: hns3: fix for getting autoneg in hns3_get_link_ksettings

This patch fixes a bug for ethtool's get_link_ksettings().
When phy exists, we should get autoneg from phy rather than from mac.
Because the value of mac.autoneg is invalid when phy exists.

Fixes: 496d03e9 (net: hns3: Add Ethtool support to HNS3 driver)
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>