The plane atomic check implementation is identical on Gen2 (DU planes)
and Gen3 (VSP planes), but two separate functions exist as they operate
on different data structures. Refactor the code to share the
implementation.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>