ASoC: dt-bindings: mt8173-afe-pcm: Allow specifying reserved memory region

It is desirable to reserve memory for the audio frontend.

Allow the "memory-region" property, to be used to point to a reserved
memory region.

Acked-by: "Rob Herring (Arm)" <[e-mail]>
Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Signed-off-by: Chen-Yu Tsai <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/mediatek,mt8173-afe-pcm.yaml

···
   power-domains:
     maxItems: 1
 
+  memory-region:
+    description: memory region for audio DMA buffers
+    maxItems: 1
+
 required:
   - compatible
   - reg
···
                        "i2s2_m",
                        "i2s3_m",
                        "i2s3_b";
+          memory-region = <&afe_dma_mem>;
     };