dt-bindings: iio: proximity: ams,as3935: 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>
Link: https://lore.kernel.org/r/20221004115642.63749-7-krzysztof.kozlowski@linaro.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/proximity/ams,as3935.yaml

@@ -49,7 +49,10 @@ required:
   - spi-cpha
   - interrupts
 
-additionalProperties: false
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+unevaluatedProperties: false
 
 examples:
   - |