dt-bindings: spi: Convert mxs spi to json-schema

* Freescale MX233/MX28 SSP/SPI

Required properties:

- compatible: Should be "fsl,<soc>-spi", where soc is "imx23" or "imx28"

- reg: Offset and length of the register set for the device

- interrupts: Should contain SSP ERROR interrupt

- dmas: DMA specifier, consisting of a phandle to DMA controller node

  and SSP DMA channel ID.

  Refer to dma.txt and fsl-mxs-dma.txt for details.

- dma-names: Must be "rx-tx".

Optional properties:

- clock-frequency : Input clock frequency to the SPI block in Hz.

		    Default is 160000000 Hz.

Example:

ssp0: ssp@80010000 {

	#address-cells = <1>;

	#size-cells = <0>;

	compatible = "fsl,imx28-spi";

	reg = <0x80010000 0x2000>;

	interrupts = <96>;

	dmas = <&dma_apbh 0>;

	dma-names = "rx-tx";

};

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/spi/mxs-spi.yaml#

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

title: Freescale MX233/MX28 SSP/SPI

maintainers:

  - Marek Vasut <marex@denx.de>

allOf:

  - $ref: "/schemas/spi/spi-controller.yaml#"

properties:

  compatible:

    enum:

      - fsl,imx23-spi

      - fsl,imx28-spi

  reg:

    maxItems: 1

  interrupts:

    maxItems: 1

  dmas:

    maxItems: 1

  dma-names:

    const: rx-tx

  clock-frequency:

    description: input clock frequency to the SPI block in Hz.

    default: 160000000

required:

  - compatible

  - reg

  - interrupts

  - dmas

  - dma-names

unevaluatedProperties: false

examples:

  - |

    spi@80010000 {

        #address-cells = <1>;

        #size-cells = <0>;

        compatible = "fsl,imx28-spi";

        reg = <0x80010000 0x2000>;

        interrupts = <96>;

        dmas = <&dma_apbh 0>;

        dma-names = "rx-tx";

    };