Freescale i.MX audio complex with WM8962 codec

Required properties:
- compatible : "fsl,imx-audio-wm8962"
- model : The user-visible name of this sound complex
- ssi-controller : The phandle of the i.MX SSI controller
- audio-codec : The phandle of the WM8962 audio codec
- audio-routing : A list of the connections between audio components.
  Each entry is a pair of strings, the first being the connection's sink,
  the second being the connection's source. Valid names could be power
  supplies, WM8962 pins, and the jacks on the board:

  Power supplies:
   * Mic Bias

  Board connectors:
   * Mic Jack
   * Headphone Jack
   * Ext Spk

- mux-int-port : The internal port of the i.MX audio muxer (AUDMUX)
- mux-ext-port : The external port of the i.MX audio muxer

Note: The AUDMUX port numbering should start at 1, which is consistent with
hardware manual.

Example:

sound {
	compatible = "fsl,imx6q-sabresd-wm8962",
		     "fsl,imx-audio-wm8962";
	model = "wm8962-audio";
	ssi-controller = <&ssi2>;
	audio-codec = <&codec>;
		audio-routing =
		"Headphone Jack", "HPOUTL",
		"Headphone Jack", "HPOUTR",
		"Ext Spk", "SPKOUTL",
		"Ext Spk", "SPKOUTR",
		"MICBIAS", "AMIC",
		"IN3R", "MICBIAS",
		"DMIC", "MICBIAS",
		"DMICDAT", "DMIC";
	mux-int-port = <2>;
	mux-ext-port = <3>;
};