dt-bindings: watchdog: Convert i.MX7ULP to json-schema

Convert the i.MX7ULP watchdog binding to DT schema format using json-schema.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.txt

-* Freescale i.MX7ULP Watchdog Timer (WDT) Controller
-
-Required properties:
-- compatible : Should be "fsl,imx7ulp-wdt"
-- reg : Should contain WDT registers location and length
-- interrupts : Should contain WDT interrupt
-- clocks: Should contain a phandle pointing to the gated peripheral clock.
-
-Optional properties:
-- timeout-sec : Contains the watchdog timeout in seconds
-
-Examples:
-
-wdog1: watchdog@403d0000 {
-	compatible = "fsl,imx7ulp-wdt";
-	reg = <0x403d0000 0x10000>;
-	interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
-	clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
-	assigned-clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
-	assigned-clocks-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
-	timeout-sec = <40>;
-};

Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/fsl-imx7ulp-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale i.MX7ULP Watchdog Timer (WDT) Controller
+
+maintainers:
+  - Anson Huang <Anson.Huang@nxp.com>
+
+allOf:
+  - $ref: "watchdog.yaml#"
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx7ulp-wdt
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  assigned-clocks:
+    maxItems: 1
+
+  assigned-clocks-parents:
+    maxItems: 1
+
+  timeout-sec: true
+
+required:
+  - compatible
+  - interrupts
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/imx7ulp-clock.h>
+
+    watchdog@403d0000 {
+        compatible = "fsl,imx7ulp-wdt";
+        reg = <0x403d0000 0x10000>;
+        interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+        assigned-clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+        assigned-clocks-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
+        timeout-sec = <40>;
+    };
+
+...