Qt: Add menu item to perform online update

Source/Core/DolphinQt2/WiiUpdate.h

@@ -0,0 +1,14 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+
+class QWidget;
+
+namespace WiiUpdate
+{
+void PerformOnlineUpdate(const std::string& region, QWidget* parent = nullptr);
+};  // namespace WiiUpdate