dt-bindings: arm: axiado: add AX3000 EVK compatible strings

Add device tree binding schema for Axiado platforms, specifically the
AX3000 SoC and its associated evaluation board. This binding will be
used for the board-level DTS files that support the AX3000 platforms.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Harshit Shah <hshah@axiado.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/arm/axiado.yaml

@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/axiado.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Axiado Platforms
+
+maintainers:
+  - Harshit Shah <hshah@axiado.com>
+
+properties:
+  $nodename:
+    const: '/'
+  compatible:
+    oneOf:
+      - description: AX3000 based boards
+        items:
+          - enum:
+              - axiado,ax3000-evk       # Axiado AX3000 Evaluation Board
+          - const: axiado,ax3000       # Axiado AX3000 SoC
+
+additionalProperties: true