citra-qt: Move config dialog code to its own directory

src/citra_qt/configuration/configure_audio.h

@@ -0,0 +1,30 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <QWidget>
+
+namespace Ui {
+class ConfigureAudio;
+}
+
+class ConfigureAudio : public QWidget {
+    Q_OBJECT
+
+public:
+    explicit ConfigureAudio(QWidget* parent = nullptr);
+    ~ConfigureAudio();
+
+    void applyConfiguration();
+
+public slots:
+    void updateAudioDevices(int sink_index);
+
+private:
+    void setConfiguration();
+
+    std::unique_ptr<Ui::ConfigureAudio> ui;
+};