vDPA/ifcvf: implement new accessors for vq_state

This commit implements a better layout of the
live migration bar, therefore the accessors for virtqueue
state have been refactored.

This commit also add a comment to the probing-ids list,
indicating this driver drives F2000X-PL virtio-net

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20230612151420.1019504-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>