dt-bindings: remoteproc: qcom,smd-edge: Mark qcom,ipc as deprecated

Deprecate the qcom,ipc way of accessing the mailbox in favor of the
'mboxes' property.

Update the example to use mboxes.
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240425-qcom-ipc-deprecate-v1-1-a8d8034253ea@z3ntu.xyzSigned-off-by: Bjorn Andersson <andersson@kernel.org>

Documentation/devicetree/bindings/remoteproc/qcom,smd-edge.yaml

@@ -61,6 +61,7 @@ properties:
     description:
       Three entries specifying the outgoing ipc bit used for signaling the
       remote processor.
+    deprecated: true
 
   qcom,smd-edge:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -111,7 +112,7 @@ examples:
         smd-edge {
             interrupts = <GIC_SPI 156 IRQ_TYPE_EDGE_RISING>;
 
-            qcom,ipc = <&apcs 8 8>;
+            mboxes = <&apcs 8>;
             qcom,smd-edge = <1>;
         };
     };