vDPA/ifcvf: deduce VIRTIO device ID when probe

This commit deduces VIRTIO device ID as device type when probe,
then ifcvf_vdpa_get_device_id() can simply return the ID.
ifcvf_vdpa_get_features() and ifcvf_vdpa_get_config_size()
can work properly based on the device ID.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/20210419063326.3748-2-lingshan.zhu@intel.com


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>