ASoC: google: dt-bindings: modify machine bindings for two MICs case

Add a property "dmic-gpios" for switching between two MICs.
Signed-off-by: Ajye Huang <ajye_huang@compal.corp-partner.google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201106061433.1483129-2-ajye_huang@compal.corp-partner.google.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/google,sc7180-trogdor.yaml

@@ -34,6 +34,10 @@ properties:
   "#size-cells":
     const: 0
 
+  dmic-gpios:
+    maxItems: 1
+    description: GPIO for switching between DMICs
+
 patternProperties:
   "^dai-link(@[0-9])?$":
     description:
@@ -83,7 +87,7 @@ examples:
   - |
     sound {
         compatible = "google,sc7180-trogdor";
-        model = "sc7180-rt5682-max98357a-1mic";
+        model = "sc7180-rt5682-max98357a-2mic";
 
         audio-routing =
                     "Headphone Jack", "HPOL",
@@ -92,6 +96,8 @@ examples:
         #address-cells = <1>;
         #size-cells = <0>;
 
+        dmic-gpios = <&tlmm 86 0>;
+
         dai-link@0 {
             link-name = "MultiMedia0";
             reg = <0>;