ASoC: dt-bindings: Use name-prefix schema

name-prefix.txt does not exist anymore, just reference the schema instead.
Signed-off-by: NAlexander Stein <alexander.stein@mailbox.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211218143423.18768-1-alexander.stein@mailbox.orgSigned-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/simple-audio-amplifier.yaml

@@ -9,6 +9,9 @@ title: Simple Audio Amplifier Device Tree Bindings
 maintainers:
   - Jerome Brunet <jbrunet@baylibre.com>
 
+allOf:
+  - $ref: name-prefix.yaml#
+
 properties:
   compatible:
     enum:
@@ -22,10 +25,7 @@ properties:
     description: >
       power supply for the device
 
-  sound-name-prefix:
-    $ref: /schemas/types.yaml#/definitions/string
-    description: >
-      See ./name-prefix.txt
+  sound-name-prefix: true
 
 required:
   - compatible