Store a reference to the ControlInfoMap used to create a ControlList and provide an operation to retrieve it. This will be used to implement serialization of ControlList. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>