net: hns3: add PCIe FLR support for VF

This patch implements the .reset_prepare and .reset_done
ops from pci framework to support the VF FLR.

This patch uses hclgevf_set_def_reset_request() and
hclgevf_reset_event() to handle FLR, so when
hdev->default_reset_request is non zero, it means there is
some reset requseted by hclgevf_set_def_reset_request() need
to be processed. Also get the hdev from the ae_dev because
hclgevf_reset_event is called with handle being NULL.

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