arm64: dts: qcom: msm8939: Use mboxes properties for APCS

Instead of passing the syscon to the various nodes, use the mbox
interface using the mboxes property.
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240424-apcs-mboxes-v1-4-6556c47cb501@z3ntu.xyzSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/msm8939.dtsi

@@ -248,7 +248,7 @@ rpm: remoteproc {
 
 		smd-edge {
 			interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
-			qcom,ipc = <&apcs1_mbox 8 0>;
+			mboxes = <&apcs1_mbox 0>;
 			qcom,smd-edge = <15>;
 
 			rpm_requests: rpm-requests {
@@ -2067,7 +2067,7 @@ wcnss_iris: iris {
 
 			smd-edge {
 				interrupts = <GIC_SPI 142 IRQ_TYPE_EDGE_RISING>;
-				qcom,ipc = <&apcs1_mbox 8 17>;
+				mboxes = <&apcs1_mbox 17>;
 				qcom,smd-edge = <6>;
 				qcom,remote-pid = <4>;