ASoC: dt-bindings: nuvoton,nau8825: Document routing strings

Add a list of the nau8825 pin names to the binding's description to make
it self-contained and improve the user experience for board developers.

Signed-off-by: Jihed Chaibi <[e-mail]>
Acked-by: Rob Herring (Arm) <[e-mail]>
Message-ID: <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/nuvoton,nau8825.yaml

···
 maintainers:
   - John Hsu <[e-mail]>
 
+description: |
+  NAU8825 audio CODEC
+
+  Pins on the device (for linking into audio routes):
+
+    Outputs:
+      * HPOL    : Headphone Left Output
+      * HPOR    : Headphone Right Output
+      * MICBIAS : Microphone Bias Output
+
+    Inputs:
+      * MICP    : Analog Microphone Positive Input
+      * MICN    : Analog Microphone Negative Input
+
 allOf:
   - $ref: dai-common.yaml#