V4L/DVB (5670): Adding new fields to v4l2_pix_format broke the ABI, reverted that change

Reverted the change to struct v4l2_pix_format. I completely missed that
this struct was used by existing ioctls so that changing it broke the ABI.
I will have to think of another way of setting the top/left coordinates
but for now this change is reverted to preserve compatibility.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>