ASoC: dt-bindings: mt8186-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/mt8186-afe-pcm.yaml

···
   reset-names:
     const: audiosys
 
+  memory-region:
+    description: memory region for audio DMA buffers
+    maxItems: 1
+
   mediatek,apmixedsys:
     $ref: /schemas/types.yaml#/definitions/phandle
     description: The phandle of the mediatek apmixedsys controller
···
                       "top_apll12_div_tdm",
                       "top_mux_audio_h",
                       "top_clk26m_clk";
+        memory-region = <&afe_dma_mem>;
     };
 
 ...