arm64: dts: qcom: sm7180: remove assigned-clock-rate property for mdp clk

Drop the assigned clock rate property and vote on the mdp clock as per
calculated value during the usecase.

This patch is dependent on the patch ("drm/msm/disp/dpu1: set mdp clk
to the maximum frequency in opp table during probe") [1].

[1] https://lore.kernel.org/r/1647269217-14064-2-git-send-email-quic_vpolimer@quicinc.com/



Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1647919631-14447-4-git-send-email-quic_vpolimer@quicinc.com