ASoC: dt-bindings: nau8822: Add #sound-dai-cells

Add #sound-dai-cells property and reference dai-common.yaml schema, this
is required since NAU8822 can be used as a platform DAI link.

Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230719124752.248898-2-francesco@dolcini.it
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/nuvoton,nau8822.yaml

@@ -21,6 +21,9 @@ properties:
   reg:
     maxItems: 1
 
+  "#sound-dai-cells":
+    const: 0
+
   nuvoton,spk-btl:
     description:
       If set, configure the two loudspeaker outputs as a Bridge Tied Load output
@@ -31,6 +34,9 @@ required:
   - compatible
   - reg
 
+allOf:
+  - $ref: dai-common.yaml#
+
 additionalProperties: false
 
 examples: