dt-bindings: firmware: arm,scmi: support for parameter in smc/hvc call

Currently, smc/hvc calls are made with smc-id only. The parameters are
all set to zeros. This change defines a new compatible string that can
be used to pass shmem address(4KB-page, offset) as two parameters in
SMC/HVC doorbell.

This is useful when multiple scmi instances are used with common smc-id.

Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230506182428.25343-2-quic_nkela@quicinc.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Documentation/devicetree/bindings/firmware/arm,scmi.yaml

@@ -34,6 +34,10 @@ properties:
       - description: SCMI compliant firmware with ARM SMC/HVC transport
         items:
           - const: arm,scmi-smc
+      - description: SCMI compliant firmware with ARM SMC/HVC transport
+                     with shmem address(4KB-page, offset) as parameters
+        items:
+          - const: arm,scmi-smc-param
       - description: SCMI compliant firmware with SCMI Virtio transport.
                      The virtio transport only supports a single device.
         items:
@@ -299,7 +303,9 @@ else:
     properties:
       compatible:
         contains:
-          const: arm,scmi-smc
+          enum:
+            - arm,scmi-smc
+            - arm,scmi-smc-param
   then:
     required:
       - arm,smc-id