dt-bindings: display: rockchip: analogix-dp: Add support to get panel from the DP AUX bus

According to Documentation/devicetree/bindings/display/dp-aux-bus.yaml,
it is a good way to get panel through the DP AUX bus.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
Link: https://lore.kernel.org/r/20250310104114.2608063-5-damon.ding@rock-chips.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>