dt-bindings: google,cros-ec-pwm: Add the new -type compatible

Update google,cros-ec-pwm node documentation to mention the
google,cros-ec-pwm-type compatible as a valid alternative.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Author: fabiobaltieri

Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml

@@ -21,7 +21,14 @@ allOf:
 
 properties:
   compatible:
-    const: google,cros-ec-pwm
+    oneOf:
+      - description: PWM controlled using EC_PWM_TYPE_GENERIC channels.
+        items:
+          - const: google,cros-ec-pwm
+      - description: PWM controlled using CROS_EC_PWM_DT_<...> types.
+        items:
+          - const: google,cros-ec-pwm-type
+
   "#pwm-cells":
     description: The cell specifies the PWM index.
     const: 1