media: ov2685: Not delay latch for gain

Update the register 0x3503 to use 'no delay latch' for gain.
This makes sensor to output the first frame as normal rather
than a very dark one.

Signed-off-by: Shunqian Zheng <zhengsq@rock-chips.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>