dt-bindings: arm: Convert TI nspire board/soc bindings to json-schema

Convert TI NSpire SoC bindings to DT schema format using json-schema.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/nspire.txt

-TI-NSPIRE calculators
-
-Required properties:
-- compatible: Compatible property value should contain "ti,nspire".
-	CX models should have "ti,nspire-cx"
-	Touchpad models should have "ti,nspire-tp"
-	Clickpad models should have "ti,nspire-clp"
-
-Example:
-
-/ {
-	model = "TI-NSPIRE CX";
-	compatible = "ti,nspire-cx";
-	...

Documentation/devicetree/bindings/arm/ti/nspire.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/ti/nspire.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI-NSPIRE calculators
+
+maintainers:
+  - Daniel Tang <dt.tangr@gmail.com>
+
+properties:
+  $nodename:
+    const: '/'
+  compatible:
+    items:
+      - enum:
+          # CX models
+          - ti,nspire-cx
+          # Touchpad models
+          - ti,nspire-tp
+          # Clickpad models
+          - ti,nspire-clp
+...