dt-bindings: mfd: qcom,spmi-pmic: Reference pm8916 wcd analog codec schema

Now that it's been converted to YAML, reference the PM8916 wcd codec
schema.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230627-topic-more_bindings-v1-6-6b4b6cd081e5@linaro.orgSigned-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml

@@ -129,7 +129,7 @@ patternProperties:
 
   "^audio-codec@[0-9a-f]+$":
     type: object
-    additionalProperties: true # FIXME qcom,pm8916-wcd-analog-codec binding not converted yet
+    $ref: /schemas/sound/qcom,pm8916-wcd-analog-codec.yaml#
 
   "^charger@[0-9a-f]+$":
     type: object