Collect the desired ImgU pipe configuration while assigning
streams in the pipeline handler validate() function and ask the
ImgUDevice class to calculate the pipe configuration parameters.
If the requested pipe configuration results in a non-valid
configuration, return an error from the validate() function.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>