ASoC: dt-bindings: nxp, tfa989x: Add vddd-supply property

Add optional vddd-supply property to allow regulator control.
Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org>
Link: https://lore.kernel.org/r/20210528105101.508254-3-vincent.knecht@mailoo.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/nxp,tfa989x.yaml

@@ -27,6 +27,9 @@ properties:
       Used as prefix for sink/source names of the component. Must be a
       unique string among multiple instances of the same component.
 
+  vddd-supply:
+    description: regulator phandle for the VDDD power supply.
+
 required:
   - compatible
   - reg