ASoC: dt-bindings: imx-card: Add playback-only and capture-only property

Refer to audio graph card, add playback-only and capture-only property
for imx-audio-card.yaml for the case that only playback or capture is
supported.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250217021715.284951-2-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/imx-audio-card.yaml

@@ -46,6 +46,14 @@ patternProperties:
         description: see tdm-slot.txt.
         $ref: /schemas/types.yaml#/definitions/uint32
 
+      playback-only:
+        description: link is used only for playback
+        $ref: /schemas/types.yaml#/definitions/flag
+
+      capture-only:
+        description: link is used only for capture
+        $ref: /schemas/types.yaml#/definitions/flag
+
       cpu:
         description: Holds subnode which indicates cpu dai.
         type: object
@@ -71,6 +79,12 @@ patternProperties:
       - link-name
       - cpu
 
+    allOf:
+      - not:
+          required:
+            - playback-only
+            - capture-only
+
     additionalProperties: false
 
 required: