dt-bindings: bluetooth: marvell: add max-speed property

The 88W8997 bluetooth module supports setting the max-speed property.
Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Documentation/devicetree/bindings/net/marvell-bluetooth.yaml

@@ -19,9 +19,25 @@ properties:
       - mrvl,88w8897
       - mrvl,88w8997
 
+  max-speed:
+    description: see Documentation/devicetree/bindings/serial/serial.yaml
+
 required:
   - compatible
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: mrvl,88w8997
+    then:
+      properties:
+        max-speed: true
+    else:
+      properties:
+        max-speed: false
+
 additionalProperties: false
 
 examples: