Move SI_GCAdapter over to InputCommon

Source/Core/InputCommon/GCAdapter.h

@@ -0,0 +1,27 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+
+struct GCPadStatus;
+
+namespace SI_GCAdapter
+{
+
+void Init();
+void Reset();
+void ResetRumble();
+void Setup();
+void Shutdown();
+void SetAdapterCallback(std::function<void(void)> func);
+void StartScanThread();
+void StopScanThread();
+void Input(int chan, GCPadStatus* pad);
+void Output(int chan, u8 rumble_command);
+bool IsDetected();
+bool IsDriverDetected();
+
+} // end of namespace SI_GCAdapter