dt-bindings: iio: imu: adi,adis16475: use spi-peripheral-props.yaml

For devices connectable by SPI bus (e.g. already using
"spi-max-frequency" property), reference the "spi-peripheral-props.yaml"
schema to allow using all SPI device properties, even these which device
bindings author did not tried yet.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221004115642.63749-5-krzysztof.kozlowski@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/imu/adi,adis16475.yaml

@@ -79,6 +79,7 @@ required:
   - spi-cpol
 
 allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
   - if:
       properties:
         compatible:
@@ -107,7 +108,7 @@ allOf:
       dependencies:
         adi,sync-mode: [ clocks ]
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |