dt-bindings: timer: renesas: mtu2: Convert to json-schema

Convert the Renesas Multi-Function Timer Pulse Unit 2 (MTU2) Device Tree
binding documentation to json-schema.

Add missing properties.
Update the example to match reality.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/timer/renesas,mtu2.txt

-* Renesas Multi-Function Timer Pulse Unit 2 (MTU2)
-
-The MTU2 is a multi-purpose, multi-channel timer/counter with configurable
-clock inputs and programmable compare match.
-
-Channels share hardware resources but their counter and compare match value
-are independent. The MTU2 hardware supports five channels indexed from 0 to 4.
-
-Required Properties:
-
-  - compatible: must be one or more of the following:
-    - "renesas,mtu2-r7s72100" for the r7s72100 MTU2
-    - "renesas,mtu2" for any MTU2
-      This is a fallback for the above renesas,mtu2-* entries
-
-  - reg: base address and length of the registers block for the timer module.
-
-  - interrupts: interrupt specifiers for the timer, one for each entry in
-    interrupt-names.
-  - interrupt-names: must contain one entry named "tgi?a" for each enabled
-    channel, where "?" is the channel index expressed as one digit from "0" to
-    "4".
-
-  - clocks: a list of phandle + clock-specifier pairs, one for each entry
-    in clock-names.
-  - clock-names: must contain "fck" for the functional clock.
-
-
-Example: R7S72100 (RZ/A1H) MTU2 node
-
-	mtu2: timer@fcff0000 {
-		compatible = "renesas,mtu2-r7s72100", "renesas,mtu2";
-		reg = <0xfcff0000 0x400>;
-		interrupts = <0 139 IRQ_TYPE_LEVEL_HIGH>,
-			     <0 146 IRQ_TYPE_LEVEL_HIGH>,
-			     <0 150 IRQ_TYPE_LEVEL_HIGH>,
-			     <0 154 IRQ_TYPE_LEVEL_HIGH>,
-			     <0 159 IRQ_TYPE_LEVEL_HIGH>;
-		interrupt-names = "tgi0a", "tgi1a", "tgi2a", "tgi3a", "tgi4a";
-		clocks = <&mstp3_clks R7S72100_CLK_MTU2>;
-		clock-names = "fck";
-	};

Documentation/devicetree/bindings/timer/renesas,mtu2.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/renesas,mtu2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Multi-Function Timer Pulse Unit 2 (MTU2)
+
+maintainers:
+  - Geert Uytterhoeven <geert+renesas@glider.be>
+  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+
+description:
+  The MTU2 is a multi-purpose, multi-channel timer/counter with configurable clock inputs
+  and programmable compare match.
+
+  Channels share hardware resources but their counter and compare match value are
+  independent. The MTU2 hardware supports five channels indexed from 0 to 4.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - renesas,mtu2-r7s72100 # RZ/A1H
+      - const: renesas,mtu2
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    maxItems: 5
+    description: One entry for each enabled channel.
+
+  interrupt-names:
+    minItems: 1
+    items:
+      - const: tgi0a
+      - const: tgi1a
+      - const: tgi2a
+      - const: tgi3a
+      - const: tgi4a
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: fck
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r7s72100-clock.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    mtu2: timer@fcff0000 {
+            compatible = "renesas,mtu2-r7s72100", "renesas,mtu2";
+            reg = <0xfcff0000 0x400>;
+            interrupts = <GIC_SPI 107 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "tgi0a";
+            clocks = <&mstp3_clks R7S72100_CLK_MTU2>;
+            clock-names = "fck";
+            power-domains = <&cpg_clocks>;
+    };