Move solution and projects to src

src/Ryujinx.Audio/Common/AudioDeviceState.cs

@@ -0,0 +1,18 @@
+namespace Ryujinx.Audio.Common
+{
+    /// <summary>
+    /// Audio device state.
+    /// </summary>
+    public enum AudioDeviceState : uint
+    {
+        /// <summary>
+        /// The audio device is started.
+        /// </summary>
+        Started,
+
+        /// <summary>
+        /// The audio device is stopped.
+        /// </summary>
+        Stopped
+    }
+}