[PATCH v2] ASoC: dt-bindings: mediatek,mt8188-mt6359: Add mediatek,adsp property

[Fei Shao <fshao@xxxxxxxxxxxx>]

On some MediaTek SoCs, an Audio DSP (ADSP) is integrated as a separate
hardware block that leverages Sound Open Firmware (SOF) and provides
additional audio functionalities. This hardware is optional, and the
audio subsystem will still function normally when it's not present.

To enable ADSP support, a 'mediatek,adsp' property is required in the
sound card node to pass the ADSP phandle. This allows AFE to link to
ADSP when the sound card is probed.

MT8188 has ADSP integrated, so add the 'mediatek,adsp' property to
allow using it in the audio subsystem.

This fixes dtbs_check error:
  Unevaluated properties are not allowed ('mediatek,adsp' was
  unexpected)

Signed-off-by: Fei Shao <fshao@xxxxxxxxxxxx>
---
This patch is based on a previous [v1] series.
This is sent as an individual patch in v2 because the other patches in
the [v1] series are either invalid or for different purpose in different
binding, so I think it'd be better to send them separately.

[v1]:
https://lore.kernel.org/all/20241025104548.1220076-2-fshao@xxxxxxxxxxxx/

Changes in v2:
- drop `mediatek,dai-link` vendor property because its goal can be
  achieved by using the existing `audio-routing`
- update property description
- update commit message

 .../devicetree/bindings/sound/mediatek,mt8188-mt6359.yaml  | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/mediatek,mt8188-mt6359.yaml b/Documentation/devicetree/bindings/sound/mediatek,mt8188-mt6359.yaml
index f94ad0715e32..ba482747f0e6 100644
--- a/Documentation/devicetree/bindings/sound/mediatek,mt8188-mt6359.yaml
+++ b/Documentation/devicetree/bindings/sound/mediatek,mt8188-mt6359.yaml
@@ -29,6 +29,13 @@ properties:
     $ref: /schemas/types.yaml#/definitions/phandle
     description: The phandle of MT8188 ASoC platform.
 
+  mediatek,adsp:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      The phandle of the MT8188 ADSP platform, which is the optional Audio DSP
+      hardware that provides additional audio functionalities if present.
+      The AFE will link to ADSP when the phandle is provided.
+
 patternProperties:
   "^dai-link-[0-9]+$":
     type: object
-- 
2.47.0.277.g8800431eea-goog