[media] v4l: vsp1: bru: Make the background color configurable

Expose the background color to userspace through the V4L2_CID_BG_COLOR
control.

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

diff --cc drivers/media/platform/vsp1/vsp1_bru.c
Simple merge

diff --cc drivers/media/platform/vsp1/vsp1_bru.h
Simple merge