dt-bindings: watchdog: migrate rt2880 text bindings to YAML

Ralink RT2880 Watchdog bindings used text format, so migrate them to YAML.
There are some additions to the binding that were not in the original
txt file. This binding is used in RT2880, RT3050, RT3352, RT3883, RT5350,
and MT7620 SoCs. To properly align binding with driver code we need to add
to the schema 'clocks' and 'resets' properties.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230302085914.2858645-1-sergio.paracuellos@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/watchdog/ralink,rt2880-wdt.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/ralink,rt2880-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ralink Watchdog Timers
+
+maintainers:
+  - Sergio Paracuellos <sergio.paracuellos@gmail.com>
+
+allOf:
+  - $ref: watchdog.yaml#
+
+properties:
+  compatible:
+    const: ralink,rt2880-wdt
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    watchdog@100 {
+      compatible = "ralink,rt2880-wdt";
+      reg = <0x120 0x10>;
+      clocks = <&clkref>;
+      resets = <&rstctrl 8>;
+      interrupt-parent = <&intc>;
+      interrupts = <1>;
+    };

Documentation/devicetree/bindings/watchdog/rt2880-wdt.txt

-Ralink Watchdog Timers
-
-Required properties:
-- compatible: must be "ralink,rt2880-wdt"
-- reg: physical base address of the controller and length of the register range
-
-Optional properties:
-- interrupts: Specify the INTC interrupt number
-
-Example:
-
-	watchdog@120 {
-		compatible = "ralink,rt2880-wdt";
-		reg = <0x120 0x10>;
-
-		interrupt-parent = <&intc>;
-		interrupts = <1>;
-	};