net: hns3: adjust VF's reset process

Currently when VF need to reset itself, it will send a cmd to PF,
after receiving the VF reset requset, PF sends a cmd to inform
VF to enter the reset process and send a cmd to firmware to do the
actual reset for the VF, it is possible that firmware has resetted
the VF, but VF has not entered the reset process, which may cause
IO not stopped problem when firmware is resetting VF.

This patch fixes it by adjusting the VF reset process, when VF
need to reset itself, it will enter the reset process first, and
it will tell the PF to send cmd to firmware to reset itself.

Add member reset_pending to struct hclgevf_dev, which indicates that
there is reset event need to be processed by the VF's reset task, and
the VF's reset task chooses the highest-level one and clears other
low-level one when it processes reset_pending.

hclge_inform_reset_assert_to_vf function is unused now, but it will
be used to support the PF reset with VF working, so declare it in
the header file.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>