arm64: dts: qcom: sm8550-mtp: drop redundant MDP status

arm64: dts: qcom: sm8550-mtp: drop redundant MDP status

MDP in sm8550.dtsi is not disabled (although its parent MDSS is), so
board DTS does not have to enable it.

Suggested-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-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/20230516154539.238655-2-krzysztof.kozlowski@linaro.org