dt-bindings: cache: Convert marvell,{feroceon,kirkwood}-cache to DT schema

Convert the Marvell Feroceon/Kirkwood Cache binding to DT schema format.

Use "marvell,kirkwood-cache" for the filename instead as that's only
compatible used in a .dts upstream.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: Conor Dooley <[e-mail]>

Documentation/devicetree/bindings/cache/marvell,feroceon-cache.txt

···
-* Marvell Feroceon Cache
-
-Required properties:
-- compatible : Should be either "marvell,feroceon-cache" or
-  	       "marvell,kirkwood-cache".
-
-Optional properties:
-- reg        : Address of the L2 cache control register. Mandatory for
-  	       "marvell,kirkwood-cache", not used by "marvell,feroceon-cache"
-
-
-Example:
-		l2: l2-cache@20128 {
-			compatible = "marvell,kirkwood-cache";
-			reg = <0x20128 0x4>;
-		};

Documentation/devicetree/bindings/cache/marvell,kirkwood-cache.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cache/marvell,kirkwood-cache.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell Feroceon/Kirkwood Cache
+
+maintainers:
+  - Andrew Lunn <[e-mail]>
+  - Gregory Clement <[e-mail]>
+
+properties:
+  compatible:
+    enum:
+      - marvell,feroceon-cache
+      - marvell,kirkwood-cache
+
+  reg:
+    maxItems: 1
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: marvell,kirkwood-cache
+    then:
+      required:
+        - reg
+    else:
+      properties:
+        reg: false
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    l2-cache@20128 {
+        compatible = "marvell,kirkwood-cache";
+        reg = <0x20128 0x4>;
+    };