Add a utils::reverse() function that creates an adapter wrapping in iterable, such that range-based iteration over the adapter iterates over the iterable in reverse order. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>