dt-bindings: arm: Convert MOXA ART board/soc bindings to json-schema

Convert MOXA ART SoC bindings to DT schema format using json-schema.

Cc: Jonas Jensen <jonas.jensen@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/moxart.txt

-MOXA ART device tree bindings
-
-Boards with the MOXA ART SoC shall have the following properties:
-
-Required root node property:
-
-compatible = "moxa,moxart";
-
-Boards:
-
-- UC-7112-LX: embedded computer
-  compatible = "moxa,moxart-uc-7112-lx", "moxa,moxart"

Documentation/devicetree/bindings/arm/moxart.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/moxart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MOXA ART device tree bindings
+
+maintainers:
+  - Jonas Jensen <jonas.jensen@gmail.com>
+
+properties:
+  compatible:
+    description: UC-7112-LX embedded computer
+    items:
+      - const: moxa,moxart-uc-7112-lx
+      - const: moxa,moxart
+
+...