ASoC: rk3036: Add binding doc of inno-rk3036 codec driver

This patch add the binding document of inno-rk3036
audio codec driver.
Signed-off-by: NZhengShunQian <zhengsq@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/inno-rk3036.txt

+Inno audio codec for RK3036
+
+Inno audio codec is integrated inside RK3036 SoC.
+
+Required properties:
+- compatible : Should be "rockchip,rk3036-codec".
+- reg : The registers of codec.
+- clock-names : Should be "acodec_pclk".
+- clocks : The clock of codec.
+- rockchip,grf : The phandle of grf device node.
+
+Example:
+
+	acodec: acodec-ana@20030000 {
+		compatible = "rk3036-codec";
+		reg = <0x20030000 0x4000>;
+		rockchip,grf = <&grf>;
+		clock-names = "acodec_pclk";
+		clocks = <&cru ACLK_VCODEC>;
+	};