When the framebuffer format was queried via VIDIOC_G_FBUF,
V4L2_FBUF_FLAG_OVERLAY would only be correctly returned for certain screen
depths.
Signed-off-by: NIan Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>