arm64: dts: qcom: sm6115: add compatible fallback to mailbox

SM6115 mailbox is compatible with MSM8994.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230322174148.810938-8-krzysztof.kozlowski@linaro.org

arch/arm64/boot/dts/qcom/sm6115.dtsi

@@ -2244,7 +2244,8 @@ watchdog@f017000 {
 		};
 
 		apcs_glb: mailbox@f111000 {
-			compatible = "qcom,sm6115-apcs-hmss-global";
+			compatible = "qcom,sm6115-apcs-hmss-global",
+				     "qcom,msm8994-apcs-kpss-global";
 			reg = <0x0 0x0f111000 0x0 0x1000>;
 
 			#mbox-cells = <1>;