net: hns3: get vf count by pci_sriov_get_totalvfs

This patch gets vf count by standard function pci_sriov_get_totalvfs,
instead of info from NIC HW.

Signed-off-by: Lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>