PCM512x audio CODECs

These devices support both I2C and SPI (configured with pin strapping
on the board).

Required properties:

  - compatible : One of "ti,pcm5121", "ti,pcm5122", "ti,pcm5141" or
                 "ti,pcm5142"

  - reg : the I2C address of the device for I2C, the chip select
          number for SPI.

  - AVDD-supply, DVDD-supply, and CPVDD-supply : power supplies for the
    device, as covered in bindings/regulator/regulator.txt

Optional properties:

  - clocks : A clock specifier for the clock connected as SCLK.  If this
    is absent the device will be configured to clock from BCLK.  If pll-in
    and pll-out are specified in addition to a clock, the device is
    configured to accept clock input on a specified gpio pin.

  - pll-in, pll-out : gpio pins used to connect the pll using <1>
    through <6>.  The device will be configured for clock input on the
    given pll-in pin and PLL output on the given pll-out pin.  An
    external connection from the pll-out pin to the SCLK pin is assumed.

Examples:

	pcm5122: pcm5122@4c {
		compatible = "ti,pcm5122";
		reg = <0x4c>;

		AVDD-supply = <&reg_3v3_analog>;
		DVDD-supply = <&reg_1v8>;
		CPVDD-supply = <&reg_3v3>;
	};


	pcm5142: pcm5142@4c {
		compatible = "ti,pcm5142";
		reg = <0x4c>;

		AVDD-supply = <&reg_3v3_analog>;
		DVDD-supply = <&reg_1v8>;
		CPVDD-supply = <&reg_3v3>;

		clocks = <&sck>;
		pll-in = <3>;
		pll-out = <6>;
	};