staging: xgifb: move XGINew_DataBusWidth into vb_device_info

Move the memory bus width info to vb_device_info.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>