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/atmel_ac97c.txt

@@ -0,0 +1,20 @@
+* Atmel AC97 controller
+
+Required properties:
+  - compatible: "atmel,at91sam9263-ac97c"
+  - reg: Address and length of the register set for the device
+  - interrupts: Should contain AC97 interrupt
+  - ac97-gpios: Please refer to soc-ac97link.txt, only ac97-reset is used
+Optional properties:
+  - pinctrl-names, pinctrl-0: Please refer to pinctrl-bindings.txt
+
+Example:
+sound@fffa0000 {
+       compatible = "atmel,at91sam9263-ac97c";
+       pinctrl-names = "default";
+       pinctrl-0 = <&pinctrl_ac97>;
+       reg = <0xfffa0000 0x4000>;
+       interrupts = <18 IRQ_TYPE_LEVEL_HIGH 5>;
+
+       ac97-gpios = <&pioB 0 0 &pioB 2 0 &pioC 29 GPIO_ACTIVE_LOW>;
+};