drm/rockchip: analogix_dp: split the lcdc select setting into device data

eDP controller need to declare which vop provide the video source,
and it's defined in GRF registers.

But different chips have different GRF register address, so we need to
create a device data to declare the GRF messages for each chips.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Acked-by: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>