dt-bindings: iio: gyroscope: bosch,bmg160: add spi-max-frequency

Make use of the common spi-peripheral-props.yaml to pull in the common
spi device properties and limit the spi-max-frequency to 10 MHz as this
is the max. frequency if VDDIO >= 1.62V.

Note all listed devices can either operate in I2C or in SPI mode.

Signed-off-by: Marco Felsch <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml

···
   vdd-supply: true
   vddio-supply: true
 
+  spi-max-frequency:
+    maximum: 10000000
+
   interrupts:
     minItems: 1
     maxItems: 2
···
   - compatible
   - reg
 
-additionalProperties: false
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+unevaluatedProperties: false
 
 examples:
   - |