arm64: dts: qcom: sdm660: Add compat qcom,sdm660-dsi-ctrl

Add silicon specific compatible qcom,sdm660-dsi-ctrl to the
mdss-dsi-ctrl block. This allows us to differentiate the specific bindings
for sdm660 against the yaml documentation.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221223021025.1646636-17-bryan.odonoghue@linaro.org

arch/arm64/boot/dts/qcom/sdm660.dtsi

@@ -154,7 +154,8 @@ mdp5_intf2_out: endpoint {
 
 &mdss {
 	dsi1: dsi@c996000 {
-		compatible = "qcom,mdss-dsi-ctrl";
+		compatible = "qcom,sdm660-dsi-ctrl",
+			     "qcom,mdss-dsi-ctrl";
 		reg = <0x0c996000 0x400>;
 		reg-names = "dsi_ctrl";