virtio_ring: advertize packed ring layout

Advertize the packed ring layout support.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/virtio/virtio_ring.c

@@ -2211,6 +2211,8 @@ void vring_transport_features(struct virtio_device *vdev)
 			break;
 		case VIRTIO_F_IOMMU_PLATFORM:
 			break;
+		case VIRTIO_F_RING_PACKED:
+			break;
 		default:
 			/* We don't understand this bit. */
 			__virtio_clear_bit(vdev, i);