dt-bindings: sound: tlv320adcx140: Add GPI config property

Add an array property that configures the General Purpose Input (GPI)
register.  The device has 4 GPI pins and each pin can be configured in 1
of 7 different ways.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200526200917.10385-1-dmurphy@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/tlv320adcx140.yaml

@@ -86,6 +86,32 @@ properties:
           maximum: 1
         default: [0, 0, 0, 0]
 
+  ti,gpi-config:
+    description: |
+       Defines the configuration for the general purpose input pins (GPI).
+       The array is defined as <GPI1 GPI2 GPI3 GPI4>.
+
+       0 - (default) disabled
+       1 - GPIX is configured as a general-purpose input (GPI)
+       2 - GPIX is configured as a master clock input (MCLK)
+       3 - GPIX is configured as an ASI input for daisy-chain (SDIN)
+       4 - GPIX is configured as a PDM data input for channel 1 and channel
+            (PDMDIN1)
+       5 - GPIX is configured as a PDM data input for channel 3 and channel
+            (PDMDIN2)
+       6 - GPIX is configured as a PDM data input for channel 5 and channel
+            (PDMDIN3)
+       7 - GPIX is configured as a PDM data input for channel 7 and channel
+            (PDMDIN4)
+
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+      - minItems: 1
+        maxItems: 4
+        items:
+          maximum: 1
+        default: [0, 0, 0, 0]
+
 required:
   - compatible
   - reg
@@ -101,6 +127,7 @@ examples:
         reg = <0x4c>;
         ti,mic-bias-source = <6>;
         ti,pdm-edge-select = <0 1 0 1>;
+        ti,gpi-config = <4 5 6 7>;
         reset-gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
       };
     };