ZTE ZX296702 I2S controller

Required properties:
 - compatible : Must be "zte,zx296702-i2s"
 - reg : Must contain I2S core's registers location and length
 - clocks : Pairs of phandle and specifier referencing the controller's clocks.
 - clock-names: "tx" for the clock to the I2S interface.
 - dmas: Pairs of phandle and specifier for the DMA channel that is used by
   the core. The core expects two dma channels for transmit.
 - dma-names : Must be "tx" and "rx"

For more details on the 'dma', 'dma-names', 'clock' and 'clock-names' properties
please check:
	* resource-names.txt
	* clock/clock-bindings.txt
	* dma/dma.txt

Example:
	i2s0: i2s0@0b005000 {
		#sound-dai-cells = <0>;
		compatible = "zte,zx296702-i2s";
		reg = <0x0b005000 0x1000>;
		clocks = <&lsp0clk ZX296702_I2S0_DIV>;
		clock-names = "tx";
		interrupts = <GIC_SPI 22 IRQ_TYPE_LEVEL_HIGH>;
		dmas = <&dma 5>, <&dma 6>;
		dma-names = "tx", "rx";
		status = "okay";
	};

	sound {
		compatible = "simple-audio-card";
		simple-audio-card,name = "zx296702_snd";
		simple-audio-card,format = "left_j";
		simple-audio-card,bitclock-master = <&sndcodec>;
		simple-audio-card,frame-master = <&sndcodec>;
		sndcpu: simple-audio-card,cpu {
			sound-dai = <&i2s0>;
		};

		sndcodec: simple-audio-card,codec {
			sound-dai = <&acodec>;
		};
	};
