Config: Move the 'Display' settings from ConfigManager to the layered config system

Source/Core/Core/ConfigLoaders/GameConfigLoader.cpp

@@ -84,6 +84,7 @@ static const INIToSectionMap& GetINIToSectionMap()
 {
   static const INIToSectionMap ini_to_section = {
       {"Core", {Config::System::Main, "Core"}},
+      {"Display", {Config::System::Main, "Display"}},
       {"Video_Hardware", {Config::System::GFX, "Hardware"}},
       {"Video_Settings", {Config::System::GFX, "Settings"}},
       {"Video_Enhancements", {Config::System::GFX, "Enhancements"}},