ASoC: tlv320adcx140: Add ASI Tx drive

Add a property to indicate if the device is to go into a High-z state on
the Tx ASI output pins when the device is idle.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200915190606.1744-3-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/tlv320adcx140.yaml

@@ -108,6 +108,12 @@ properties:
       maximum: 7
     default: [0, 0, 0, 0]
 
+  ti,asi-tx-drive:
+    type: boolean
+    description: |
+      When set the device will set the Tx ASI output to a Hi-Z state for unused
+      data cycles. Default is to drive the output low on unused ASI cycles.
+
 patternProperties:
   '^ti,gpo-config-[1-4]$':
     $ref: /schemas/types.yaml#/definitions/uint32-array