spi: dt-bindings: cadence: Add Marvell overlay bindings documentation for Cadence XSPI

Add new bindings for the v2 Marvell xSPI overlay: marvell,cn10-xspi-nor
compatible string. This new compatible string distinguishes between the
original and modified xSPI block.

Also add an optional base for the xfer register set with an additional
reg field to allocate the xSPI Marvell overlay XFER block.

Signed-off-by: Witold Sadowski <wsadowski@marvell.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240724154739.582367-2-wsadowski@marvell.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/cdns,xspi.yaml

@@ -15,24 +15,27 @@ description: |
   single, dual, quad or octal wire transmission modes for
   read/write access to slaves such as SPI-NOR flash.
 
-allOf:
-  - $ref: spi-controller.yaml#
-
 properties:
   compatible:
-    const: cdns,xspi-nor
+    enum:
+      - cdns,xspi-nor
+      - marvell,cn10-xspi-nor
 
   reg:
     items:
       - description: address and length of the controller register set
       - description: address and length of the Slave DMA data port
       - description: address and length of the auxiliary registers
+      - description: address and length of the xfer registers
+    minItems: 3
 
   reg-names:
     items:
       - const: io
       - const: sdma
       - const: aux
+      - const: xfer
+    minItems: 3
 
   interrupts:
     maxItems: 1
@@ -42,6 +45,27 @@ required:
   - reg
   - interrupts
 
+allOf:
+  - $ref: spi-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - marvell,cn10-xspi-nor
+    then:
+      properties:
+        reg:
+          minItems: 4
+        reg-names:
+          minItems: 4
+    else:
+      properties:
+        reg:
+          maxItems: 3
+        reg-names:
+          maxItems: 3
+
 unevaluatedProperties: false
 
 examples: