dt-bindings: iio: frequency: Add docs for ADF4371 PLL

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/iio/frequency/adf4371.yaml#

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

title: Analog Devices ADF4371 Wideband Synthesizer

maintainers:

  - Popa Stefan <stefan.popa@analog.com>

description: |

  Analog Devices ADF4371 SPI Wideband Synthesizer

  https://www.analog.com/media/en/technical-documentation/data-sheets/adf4371.pdf

properties:

  compatible:

    enum:

      - adi,adf4371

  reg:

    maxItems: 1

  clocks:

    description:

      Definition of the external clock (see clock/clock-bindings.txt)

    maxItems: 1

  clock-names:

    description:

      Must be "clkin"

    maxItems: 1

required:

  - compatible

  - reg

  - clocks

  - clock-names

examples:

  - |

    spi0 {

        #address-cells = <1>;

        #size-cells = <0>;

        frequency@0 {

                compatible = "adi,adf4371";

                reg = <0>;

                spi-max-frequency = <1000000>;

                clocks = <&adf4371_clkin>;

                clock-names = "clkin";

        };

    };

...