ROCKCHIP Built-in HDMI and external audio codec which use the same
I2S interface(such as RK3368)
Use simple-audio-card can be if only HDMI or codec ic

Required properties:
- compatible: "rockchip,rk3368-hdmi-analog"
- rockchip,cpu: The phandle of the Rockchip I2S controller that's
  connected to the CODEC
- rockchip,codec: The phandle of audio codecs, should contain both
  codec ic and HDMI

Example:

sound {
	compatible = "rockchip,rk3368-hdmi-analog";
	rockchip,cpu = <&i2s_8ch>;
	rockchip,codec = <&es8316>, <&hdmi>;
	rockchip,widgets = "Microphone", "Mic Jack",
			   "Headphone", "Headphone Jack";
	rockchip,routing = "Mic Jack", "micbias",
			   "Headphone Jack", "HPOL",
			   "Headphone Jack", "HPOR";
};