The test results show that the maximum time of hardware return
to mac link state is 500MS.The software needs to set twice the
maximum time of hardware return state (1000MS).

If not modified, the loopback test returns probability failure.
Signed-off-by: Nliuzhongzhu <liuzhongzhu@huawei.com>
Signed-off-by: NPeng Li <lipeng321@huawei.com>
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>