media: Documentation: Mention CCS tools

CCS tools is a useful set of programs and libraries for working with CCS
static data. Do mention that in context of the CCS driver.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>