dt-bindings: rng: ti,omap-rom-rng: convert OMAP ROM RNG to dtschema

Convert the OMAP ROM RNG bindings to DT schema.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211227183251.132525-6-krzysztof.kozlowski@canonical.com

Documentation/devicetree/bindings/rng/omap3_rom_rng.txt

-OMAP ROM RNG driver binding
-
-Secure SoCs may provide RNG via secure ROM calls like Nokia N900 does. The
-implementation can depend on the SoC secure ROM used.
-
-- compatible:
-	Usage: required
-	Value type: <string>
-	Definition: must be "nokia,n900-rom-rng"
-
-- clocks:
-	Usage: required
-	Value type: <prop-encoded-array>
-	Definition: reference to the the RNG interface clock
-
-- clock-names:
-	Usage: required
-	Value type: <stringlist>
-	Definition: must be "ick"
-
-Example:
-
-	rom_rng: rng {
-		compatible = "nokia,n900-rom-rng";
-		clocks = <&rng_ick>;
-		clock-names = "ick";
-	};

Documentation/devicetree/bindings/rng/ti,omap-rom-rng.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/ti,omap-rom-rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: OMAP ROM Random Number Generator
+
+maintainers:
+  - Pali Rohár <pali@kernel.org>
+  - Tony Lindgren <tony@atomide.com>
+
+description:
+  Secure SoCs may provide RNG via secure ROM calls like Nokia N900 does.
+  The implementation can depend on the SoC secure ROM used.
+
+properties:
+  compatible:
+    const: nokia,n900-rom-rng
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: ick
+
+required:
+  - compatible
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    rng {
+        compatible = "nokia,n900-rom-rng";
+        clocks = <&rng_ick>;
+        clock-names = "ick";
+    };