Fix things mentioned during code review

Ref: https://github.com/dolphin-emu/dolphin/pull/4917

Source/Core/Common/Config/Enums.h

@@ -0,0 +1,32 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+namespace Config
+{
+enum class LayerType
+{
+  Base,
+  GlobalGame,
+  LocalGame,
+  Movie,
+  Netplay,
+  CommandLine,
+  CurrentRun,
+  Meta,
+};
+
+enum class System
+{
+  Main,
+  GCPad,
+  WiiPad,
+  GCKeyboard,
+  GFX,
+  Logger,
+  Debugger,
+  UI,
+};
+}