arm64: dts: qcom: add mdp_clk clock to the MDSS device

Add MDP_CLK ("core") clock to the mdss device to allow MDSS driver to
access HW_REV/etc registers.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220615135935.87381-5-dmitry.baryshkov@linaro.org

arch/arm64/boot/dts/qcom/msm8996.dtsi

@@ -795,8 +795,9 @@ mdss: mdss@900000 {
 			interrupt-controller;
 			#interrupt-cells = <1>;
 
-			clocks = <&mmcc MDSS_AHB_CLK>;
-			clock-names = "iface";
+			clocks = <&mmcc MDSS_AHB_CLK>,
+				 <&mmcc MDSS_MDP_CLK>;
+			clock-names = "iface", "core";
 
 			#address-cells = <1>;
 			#size-cells = <1>;