arm64: dts: qcom: sm8350: Hook up DSI1 to MDP

Somehow DSI1 was not hooked up to MDP resulting in it not working.
Fix it.

Fixes: d4a44105 ("arm64: dts: qcom: sm8350: Add display system nodes")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230120210101.2146852-8-konrad.dybcio@linaro.org