ASoC: tlv320aic3x: Rename property for reset GPIO

The property used to specify a GPIO intended for reset is "reset-gpios",
but this binding uses "gpio-reset".  It is not compatible with newer
methods used to fetch GPIO pins and to prevent the spread of this error
to other bindings let's rename to be more standard.

We also standardize the pin as active-low, different device trees have
marked the GPIO different ways, luckily the driver currently uses the
low-level GPIO set function which does not respect the active-low flag,
but future changes may change this. This is an active-low reset, mark
it as such.

Lastly, add an example of use for this property.

[Rewrote title & first paragraph for clarity & accuracy -- broonie]
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/tlv320aic3x.txt

@@ -17,7 +17,7 @@ Required properties:
 
 Optional properties:
 
-- gpio-reset - gpio pin number used for codec reset
+- reset-gpios - GPIO specification for the active low RESET input.
 - ai3x-gpio-func - <array of 2 int> - AIC3X_GPIO1 & AIC3X_GPIO2 Functionality
 				    - Not supported on tlv320aic3104
 - ai3x-micbias-vg - MicBias Voltage required.
@@ -34,6 +34,10 @@ Optional properties:
 - AVDD-supply, IOVDD-supply, DRVDD-supply, DVDD-supply : power supplies for the
   device as covered in Documentation/devicetree/bindings/regulator/regulator.txt
 
+Deprecated properties:
+
+- gpio-reset - gpio pin number used for codec reset
+
 CODEC output pins:
   * LLOUT
   * RLOUT
@@ -61,10 +65,14 @@ The pins can be used in referring sound node's audio-routing property.
 
 Example:
 
+#include <dt-bindings/gpio/gpio.h>
+
 tlv320aic3x: tlv320aic3x@1b {
 	compatible = "ti,tlv320aic3x";
 	reg = <0x1b>;
 
+	reset-gpios = <&gpio1 17 GPIO_ACTIVE_LOW>;
+
 	AVDD-supply = <&regulator>;
 	IOVDD-supply = <&regulator>;
 	DRVDD-supply = <&regulator>;