dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/sound/cs4270.txt

@@ -0,0 +1,21 @@
+CS4270 audio CODEC
+
+The driver for this device currently only supports I2C.
+
+Required properties:
+
+  - compatible : "cirrus,cs4270"
+
+  - reg : the I2C address of the device for I2C
+
+Optional properties:
+
+  - reset-gpios : a GPIO spec for the reset pin. If specified, it will be
+		  deasserted before communication to the codec starts.
+
+Example:
+
+codec: cs4270@48 {
+	compatible = "cirrus,cs4270";
+	reg = <0x48>;
+};