To prepare for storing more information about pixel formats in PixelFormatInfo, move the class to formats.cpp and document it. The pixel formats database is moved to the same file, and a new static function is added to PixelFormatInfo to retrieve a PixelFormatInfo for a PixelFormat. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>