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

* Freescale i.MX Watchdog Timer (WDT) Controller

Required properties:

- compatible : Should be "fsl,<soc>-wdt"

- reg : Should contain WDT registers location and length

- interrupts : Should contain WDT interrupt

Optional properties:

- big-endian: If present the watchdog device's registers are implemented

  in big endian mode, otherwise in native mode(same with CPU), for more

  detail please see: Documentation/devicetree/bindings/regmap/regmap.txt.

- fsl,ext-reset-output: If present the watchdog device is configured to

  assert its external reset (WDOG_B) instead of issuing a software reset.

- timeout-sec : Contains the watchdog timeout in seconds

Examples:

wdt@73f98000 {

	compatible = "fsl,imx51-wdt", "fsl,imx21-wdt";

	reg = <0x73f98000 0x4000>;

	interrupts = <58>;

	big-endian;

	timeout-sec = <20>;

};

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/watchdog/fsl-imx-wdt.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Freescale i.MX Watchdog Timer (WDT) Controller

maintainers:

  - Anson Huang <Anson.Huang@nxp.com>

allOf:

  - $ref: "watchdog.yaml#"

properties:

  compatible:

    enum:

      - fsl,imx21-wdt

  reg:

    maxItems: 1

  interrupts:

    maxItems: 1

  clocks:

    maxItems: 1

  fsl,ext-reset-output:

    $ref: /schemas/types.yaml#/definitions/flag

    description: |

      If present, the watchdog device is configured to assert its

      external reset (WDOG_B) instead of issuing a software reset.

required:

  - compatible

  - interrupts

  - reg

unevaluatedProperties: false

examples:

  - |

    #include <dt-bindings/interrupt-controller/arm-gic.h>

    #include <dt-bindings/clock/imx6qdl-clock.h>

    watchdog@20bc000 {

        compatible = "fsl,imx21-wdt";

        reg = <0x020bc000 0x4000>;

        interrupts = <0 80 IRQ_TYPE_LEVEL_HIGH>;

        clocks = <&clks IMX6QDL_CLK_IPG>;

    };

...