net: hns3: add link change event report

Previously, PF updates link status per second. For some scenario,
it requires link down event being reported more quickly.
To solve it, firmware pushes the link change event to PF with
CMDQ message, and driver updates the link status directly.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Reviewed-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>