This patch uses a reserved byte in the hclge_mbx_vf_to_pf_cmd
to save the need_resp flag, so when PF received the mailbox,
it can use it to decise whether send a response to VF.

For hclge_set_vf_uc_mac_addr(), it should use mbx_need_resp flag
to decide whether send response to VF.
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NPeng Li <lipeng321@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>