media: rcar-isp: Move driver to own directory

media: rcar-isp: Move driver to own directory

Before extending the driver with functions from the R-Car ISP core that
will span multiple files move the existing driver to a separate
directory. While at it rename the single source file to allow future
files to be grouped by functions.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20250423163113.2961049-6-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>