Spreadtrum Communications UCP1301 smart pa bindings

UCP1301 is a high performance, low noise analog audio smart
amplifier with current and voltage sensing ADC inside, which
specialized in music and audio applications with speaker temperature
and membrane excursion protection to avoid speaker damage.

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Required properties:
- compatible : Should be one of following "sprd,ucp1301-spk", "sprd,ucp1301-spk2", "sprd,ucp1301-rcv"
- reg: I2C slave address, 0x58.
- reset-gpios: a GPIO spec for the reset pin.
- #sound-dai-cells : it used to specify how many cells used when using dai phandle.
	if equal 0 means using default dai 0, if equal 1,
	the dai number is determined by the second parameter of sound-dai property.
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Example:

	ucp1301_smartpa: ucp1301@58 {
		compatible = "sprd,ucp1301-spk";
		reg = <0x58>;
		reset-gpios = <&ap_gpio 134 GPIO_ACTIVE_HIGH>;
		#sound-dai-cells = <1>;
	};
