media: ov08x40: Modify the tline calculation in different modes

ov08x40 quad bayer sensor ISP has the following work modes:
- normal mode: full size
- 2x2 binned mode: binning size

In normal and binned modes, different tline calculations are
applied.

- normal mode: Tline value needs to be doubled as per the
vendor's update.

Tline time = 2 * HTS / SCLK
Exposure unit : 1 * HTS = 0.5 Tline

- 2x2 binned mode:

Tline time = 1 * HTS / SCLK
Exposure unit : 1 * HTS = 1 Tline

Signed-off-by: Jason Chen <jason.z.chen@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>