* NXP TFA9890

The TFA9890 is a high efficiency class-D audio amplifier with a sophisticated
SpeakerBoost protection algorithm

Required properties:
 - compatible:
		the string of "nxp,tfa9890"
 - reg:
		the i2c slave address of the IC
 - gpios:
		an array specifiying the two required GPIOs for operation.
			- RESET GPIO
 - tfa_vd-supply:
		specify the regulator it uses.
 - tfa_max-vol-steps:
		specify the max vol steps used on the platform

Example:
		tfa9890@34 {
			compatible = "nxp,tfa9890";
			reg = <0x34>;
			gpios = <&pm8921_gpio 18 0>;     /* RESET */
			tfa_vdd-supply = <&rpm_8921_s4>;
			nxp,tfa_max-vol-steps = <15>;
		};