dt-bindings: rng: timeriomem_rng: convert TimerIO RNG to dtschema

Convert the TimerIO 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/20211227183251.132525-8-krzysztof.kozlowski@canonical.com

Documentation/devicetree/bindings/rng/timeriomem_rng.txt

-HWRNG support for the timeriomem_rng driver
-
-Required properties:
-- compatible : "timeriomem_rng"
-- reg : base address to sample from
-- period : wait time in microseconds to use between samples
-
-Optional properties:
-- quality : estimated number of bits of true entropy per 1024 bits read from the
-            rng.  Defaults to zero which causes the kernel's default quality to
-            be used instead.  Note that the default quality is usually zero
-            which disables using this rng to automatically fill the kernel's
-            entropy pool.
-
-N.B. currently 'reg' must be at least four bytes wide and 32-bit aligned
-
-Example:
-
-hwrng@44 {
-	#address-cells = <1>;
-	#size-cells = <1>;
-	compatible = "timeriomem_rng";
-	reg = <0x44 0x04>;
-	period = <1000000>;
-};

Documentation/devicetree/bindings/rng/timeriomem_rng.yaml

+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/timeriomem_rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TimerIO Random Number Generator
+
+maintainers:
+  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+
+properties:
+  compatible:
+    const: timeriomem_rng
+
+  period:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: wait time in microseconds to use between samples
+
+  quality:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0
+    description:
+      Estimated number of bits of true entropy per 1024 bits read from the rng.
+      Defaults to zero which causes the kernel's default quality to be used
+      instead.  Note that the default quality is usually zero which disables
+      using this rng to automatically fill the kernel's entropy pool.
+
+  reg:
+    maxItems: 1
+    description:
+      Base address to sample from. Currently 'reg' must be at least four bytes
+      wide and 32-bit aligned.
+
+required:
+  - compatible
+  - period
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    rng@44 {
+        compatible = "timeriomem_rng";
+        reg = <0x44 0x04>;
+        period = <1000000>;
+    };