[media] v4l: vsp1: Split display list manager from display list

This clarifies the API and prepares display list support for being used
to implement the request API.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
9 files changed