net: hns3: disable mac in flr process

The firmware will not disable mac in flr process. Therefore, the driver
needs to proactively disable mac during flr, which is the same as the
function reset.

Fixes: 35d93a30 ("net: hns3: adjust the process of PF reset")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>