Rockchip VOP couldn't output YUV video format for eDP controller, so when driver detect connector support YUV video format, we need to hack it down to RGB888. Signed-off-by: Yakir Yang <ykk@rock-chips.com> Acked-by: Mark Yao <mark.yao@rock-chips.com> Reviewed-by: Tomasz Figa <tomasz.figa@chromium.com> Reviewed-by: Sean Paul <seanpaul@chromium.org>