Texas Instruments TWL family (twl4030) audio module

The audio module inside the TWL family consist of an audio codec and a vibra
driver.

Required properties:
- compatible : must be "ti,twl4030-audio"

Optional properties, nodes:

Audio functionality:
- codec { }: Need to be present if the audio functionality is used. Within this
	     section the following options can be used:
- ti,digimic_delay: Delay need after enabling the digimic to reduce artifacts
		    from the start of the recorded sample (in ms)
-ti,ramp_delay_value: HS ramp delay configuration to reduce pop noise
-ti,hs_extmute: Use external mute for HS pop reduction
-ti,hs_extmute_gpio: Use external GPIO to control the external mute
-ti,offset_cncl_path: Offset cancellation path selection, refer to TRM for the
		      valid values.

Vibra functionality
- ti,enable-vibra: Need to be set to <1> if the vibra functionality is used. if
		   missing or it is 0, the vibra functionality is disabled.

Example:
&i2c1 {
	clock-frequency = <2600000>;

	twl: twl@48 {
		reg = <0x48>;
		interrupts = <7>; /* SYS_NIRQ cascaded to intc */
		interrupt-parent = <&intc>;

		twl_audio: audio {
			compatible = "ti,twl4030-audio";

			ti,enable-vibra = <1>;

			codec {
				ti,ramp_delay_value = <3>;
			};

		};
	};
};