arm64: dts: qcom: sc7280: Add compat qcom,sc7280-dsi-ctrl

Add silicon specific compatible qcom,sc7280-dsi-ctrl to the
mdss-dsi-ctrl block. This allows us to differentiate the specific bindings
for sc7280 against the yaml documentation.
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221223021025.1646636-15-bryan.odonoghue@linaro.org

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

@@ -3909,7 +3909,8 @@ opp-506666667 {
 			};
 
 			mdss_dsi: dsi@ae94000 {
-				compatible = "qcom,mdss-dsi-ctrl";
+				compatible = "qcom,sc7280-dsi-ctrl",
+					     "qcom,mdss-dsi-ctrl";
 				reg = <0 0x0ae94000 0 0x400>;
 				reg-names = "dsi_ctrl";