dt-bindings: iio: adc: maxim,max1118 yaml conversion

* MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs

Required properties:

 - compatible: Should be one of

	* "maxim,max1117"

	* "maxim,max1118"

	* "maxim,max1119"

 - reg: spi chip select number for the device

 - (max1118 only) vref-supply: The regulator supply for ADC reference voltage

Recommended properties:

 - spi-max-frequency: Definition as per

		Documentation/devicetree/bindings/spi/spi-bus.txt

Example:

adc@0 {

	compatible = "maxim,max1118";

	reg = <0>;

	vref-supply = <&vdd_supply>;

	spi-max-frequency = <1000000>;

};

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/iio/adc/maxim,max1118.yaml#

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

title: Maxim MAX1118 and similar ADCs

maintainers:

  - Akinobu Mita <akinobu.mita@gmail.com>

description: |

    Dual channel 8bit ADCs.

properties:

  compatible:

    enum:

      - maxim,max1117

      - maxim,max1118

      - maxim,max1119

  reg:

    maxItems: 1

  spi-max-frequency:

    maximum: 5000000

  vref-supply:

    description: External reference, needed to establish input scaling

if:

  properties:

    compatible:

      contains:

        const: maxim,max1118

then:

  required:

    - vref-supply

else:

  properties:

    vref-supply: false

required:

  - compatible

  - reg

additionalProperties: false

examples:

  - |

    spi {

        #address-cells = <1>;

        #size-cells = <0>;

        adc@0 {

            compatible = "maxim,max1118";

            reg = <0>;

            vref-supply = <&adc_vref>;

            spi-max-frequency = <1000000>;

        };

    };

...