dt-bindings: remoteproc: k3-r5f: Update bindings for J721S2 SoCs

The TI K3 J721S2 SoCs have three dual-core Arm R5F clusters/subsystems,
with 2 R5F cores each, one in MCU voltage domain and the other two in
MAIN voltage domain.

These clusters are similar to J7200 R5F clusters. Compatible info is
updated for intuitively matching to the new J721S2 SoCs.
Signed-off-by: Hari Nagalla <hnagalla@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211122122726.8532-2-hnagalla@ti.comSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml

@@ -38,6 +38,7 @@ properties:
       - ti,j721e-r5fss
       - ti,j7200-r5fss
       - ti,am64-r5fss
+      - ti,j721s2-r5fss
 
   power-domains:
     description: |
@@ -64,9 +65,9 @@ properties:
     description: |
       Configuration Mode for the Dual R5F cores within the R5F cluster.
       Should be either a value of 1 (LockStep mode) or 0 (Split mode) on
-      most SoCs (AM65x, J721E, J7200), default is LockStep mode if omitted;
-      and should be either a value of 0 (Split mode) or 2 (Single-CPU mode)
-      on AM64x SoCs, default is Split mode if omitted.
+      most SoCs (AM65x, J721E, J7200, J721s2), default is LockStep mode if
+      omitted; and should be either a value of 0 (Split mode) or 2
+      (Single-CPU mode) on AM64x SoCs, default is Split mode if omitted.
 
 # R5F Processor Child Nodes:
 # ==========================
@@ -104,6 +105,7 @@ patternProperties:
           - ti,j721e-r5f
           - ti,j7200-r5f
           - ti,am64-r5f
+          - ti,j721s2-r5f
 
       reg:
         items: