Two documentation files are missing SPDX headers. Add them, with the CC-BY-SA-4.0 license that covers all the libcamera documentation. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>