arm64: dts: qcom: sm7280: 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/1647919631-14447-3-git-send-email-quic_vpolimer@quicinc.com

arch/arm64/boot/dts/qcom/sc7280.dtsi

@@ -3426,9 +3426,6 @@ mdss: display-subsystem@ae00000 {
 				      "ahb",
 				      "core";
 
-			assigned-clocks = <&dispcc DISP_CC_MDSS_MDP_CLK>;
-			assigned-clock-rates = <300000000>;
-
 			interrupts = <GIC_SPI 83 IRQ_TYPE_LEVEL_HIGH>;
 			interrupt-controller;
 			#interrupt-cells = <1>;
@@ -3462,11 +3459,9 @@ mdss_mdp: display-controller@ae01000 {
 					      "lut",
 					      "core",
 					      "vsync";
-				assigned-clocks = <&dispcc DISP_CC_MDSS_MDP_CLK>,
-						<&dispcc DISP_CC_MDSS_VSYNC_CLK>,
+				assigned-clocks = <&dispcc DISP_CC_MDSS_VSYNC_CLK>,
 						<&dispcc DISP_CC_MDSS_AHB_CLK>;
-				assigned-clock-rates = <300000000>,
-							<19200000>,
+				assigned-clock-rates = <19200000>,
 							<19200000>;
 				operating-points-v2 = <&mdp_opp_table>;
 				power-domains = <&rpmhpd SC7280_CX>;