dt-bindings: display: bridge: it6505: Add #sound-dai-cells

The ITE IT6505 display bridge can take one I2S input and transmit it
over the DisplayPort link.

Add #sound-dai-cells (= 0) to the binding for it.

Signed-off-by: Chen-Yu Tsai <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Douglas Anderson <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml

···
 maintainers:
   - Allen Chen <[e-mail]>
 
+allOf:
+  - $ref: /schemas/sound/dai-common.yaml#
+
 description: |
   The IT6505 is a high-performance DisplayPort 1.1a transmitter,
   fully compliant with DisplayPort 1.1a, HDCP 1.3 specifications.
···
   extcon:
     maxItems: 1
     description: extcon specifier for the Power Delivery
+
+  "#sound-dai-cells":
+    const: 0
 
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
···
   - extcon
   - ports
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |