ASoC: tlv320aic32x4: DT support

Add DT support for this codec. The bindings differ a bit from the aic3x
codec bindings, so I created a new binding documentation.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/Documentation/devicetree/bindings/sound/tlv320aic32x4.txt b/Documentation/devicetree/bindings/sound/tlv320aic32x4.txt
new file mode 100644
index 0000000..db05510
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/tlv320aic32x4.txt
@@ -0,0 +1,18 @@
+Texas Instruments - tlv320aic32x4 Codec module
+
+The tlv320aic32x4 serial control bus communicates through I2C protocols
+
+Required properties:
+ - compatible: Should be "ti,tlv320aic32x4"
+ - reg: I2C slave address
+
+Optional properties:
+ - reset-gpios: Reset-GPIO phandle with args as described in gpio/gpio.txt
+
+
+Example:
+
+codec: tlv320aic32x4@18 {
+	compatible = "ti,tlv320aic32x4";
+	reg = <0x18>;
+};