[media] v4l: vsp1: Split pipeline management code from vsp1_video.c

The code will be used to control the vsp1 driver from the DU driver
without using video nodes.

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