s390x/virtio-ccw: support virtio-1 set_vq format Support the new CCW_CMD_SET_VQ format for virtio-1 devices. While we're at it, refactor the code a bit and enforce big endian fields (which had always been required, even for legacy). Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>