media: atomisp-ov2680: Fix ov2680_set_fmt() messing up high exposure settings

For exposure settings > (lines_per_frame - vts_margin) the VTS register
needs to be programmed to (exposure + vts_margin) rather then being
set to lines_per_frame.

The res->regs register array was clobbering this higher setting causing
high exposure settings to not work. Fix this by letting ov2680_set_fmt()
calculate the vts value, instead of hardcoding it.

This is the last in a series of fixes which fixes exposure and gain
settings not working, with this everything works, so drop the comment
that it does not work.

Link: https://lore.kernel.org/linux-media/20211107171549.267583-12-hdegoede@redhat.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>