Dialog Semiconductor DA7213 Audio Codec bindings

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Required properties:
- compatible : Should be "dlg,da7213"
- reg: Specifies the I2C slave address

Optional properties:
- clocks : phandle and clock specifier for codec MCLK.
- clock-names : Clock name string for 'clocks' attribute, should be "mclk".

- dlg,micbias1-lvl : Voltage (mV) for Mic Bias 1
	[<1600>, <2200>, <2500>, <3000>]
- dlg,micbias2-lvl : Voltage (mV) for Mic Bias 2
	[<1600>, <2200>, <2500>, <3000>]
- dlg,dmic-data-sel : DMIC channel select based on clock edge.
	["lrise_rfall", "lfall_rrise"]
- dlg,dmic-samplephase : When to sample audio from DMIC.
	["on_clkedge", "between_clkedge"]
- dlg,dmic-clkrate : DMIC clock frequency (Hz).
	[<1500000>, <3000000>]

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Example:

	codec_i2c: da7213@1a {
		compatible = "dlg,da7213";
 		reg = <0x1a>;

 		clocks = <&clks 201>;
		clock-names = "mclk";

		dlg,micbias1-lvl = <2500>;
		dlg,micbias2-lvl = <2500>;

		dlg,dmic-data-sel = "lrise_rfall";
		dlg,dmic-samplephase = "between_clkedge";
		dlg,dmic-clkrate = <3000000>;
	};
