dt-bindings: pwm: intel,keembay: Do not require pwm-cells twice

pwm-cells property is already required by pwm.yaml schema.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Author: krzk

Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml

@@ -31,7 +31,6 @@ required:
   - compatible
   - reg
   - clocks
-  - '#pwm-cells'
 
 additionalProperties: false