ASoC: dt-bindings: nau8822: minor updates

Merge series from Francesco Dolcini <francesco@dolcini.it>:

Minor updates to NAU8822 DT bindings:
 - Add #sound-dai-cells
 - Add MCLK

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

@@ -21,6 +21,15 @@ properties:
   reg:
     maxItems: 1
 
+  "#sound-dai-cells":
+    const: 0
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: mclk
+
   nuvoton,spk-btl:
     description:
       If set, configure the two loudspeaker outputs as a Bridge Tied Load output
@@ -31,6 +40,9 @@ required:
   - compatible
   - reg
 
+allOf:
+  - $ref: dai-common.yaml#
+
 additionalProperties: false
 
 examples: