Qt/Mapping: Implement Microphone widget

Source/Core/DolphinQt2/Config/Mapping/GCMicrophone.h

@@ -0,0 +1,29 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "DolphinQt2/Config/Mapping/MappingWidget.h"
+
+class QCheckBox;
+class QFormLayout;
+class QGroupBox;
+class QHBoxLayout;
+class QLabel;
+class QVBoxLayout;
+
+class GCMicrophone final : public MappingWidget
+{
+public:
+  explicit GCMicrophone(MappingWindow* window);
+
+  InputConfig* GetConfig() override;
+
+private:
+  void LoadSettings() override;
+  void SaveSettings() override;
+  void CreateMainLayout();
+
+  QHBoxLayout* m_main_layout;
+};