net: hns3: add wait until mac link down

net: hns3: add wait until mac link down

commit 6265e242f7b95f2c1195b42ec912b84ad161470e upstream.

In some configure flow of hns3 driver, for example, change mtu, it will
disable MAC through firmware before configuration. But firmware disables
MAC asynchronously. The rx traffic may be not stopped in this case.

So fixes it by waiting until mac link is down.

Fixes: a9775bb64aa7 ("net: hns3: fix set and get link ksettings issue")
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230807113452.474224-4-shaojijie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>