Use the cached sensor maximum resolution and the pixel format generated by the ImgU output devices as default stream configuration. While at it, replace the hardcoded numerical value for the number of buffers with a named constexpr. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>