WM8962 audio CODEC

This device supports I2C only.

Required properties:

  - compatible : "wlf,wm8962"

  - reg : the I2C address of the device.

Optional properties:
  - spk-mono: This is a boolean property. If present, the SPK_MONO bit
    of R51 (Class D Control 2) gets set, indicating that the speaker is
    in mono mode.

  - mic-cfg : Default register value for R48 (Additional Control 4).
    If absent, the default should be the register default.

  - gpio-cfg : A list of GPIO configuration register values. The list must
    be 6 entries long. If absent, no configuration of these registers is
    performed. And note that only the value within [0x0, 0xffff] is valid.
    Any other value is regarded as setting the GPIO register by its reset
    value 0x0.

Example:

codec: wm8962@1a {
	compatible = "wlf,wm8962";
	reg = <0x1a>;

	gpio-cfg = <
		0x0000 /* 0:Default */
		0x0000 /* 1:Default */
		0x0013 /* 2:FN_DMICCLK */
		0x0000 /* 3:Default */
		0x8014 /* 4:FN_DMICCDAT */
		0x0000 /* 5:Default */
	>;
};