virtio pmem: remove transitional names

Remove transitional & non transitional names for virtio pmem.
Only virtio 1.0 and up is supported.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Message-Id: <20190712073554.21918-4-pagupta@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>