drm: bridge: analogix/dp: add some rk3288 special registers setting

RK3288 need some special registers setting, we can separate
them out by the dev_type of plat_data.

Tested-by: Caesar Wang <wxt@rock-chips.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Yakir Yang <ykk@rock-chips.com>