settings: Add a new "use_extended_memory_layout" setting.

- This will be used to enable emulation of a larger memory arrangement.

src/yuzu/configuration/configure_general.h

@@ -48,6 +48,7 @@ private:
 
     ConfigurationShared::CheckState use_speed_limit;
     ConfigurationShared::CheckState use_multi_core;
+    ConfigurationShared::CheckState use_extended_memory_layout;
 
     const Core::System& system;
 };