Allow the user to enable the extended information string like the old days.

This string shows emulated CPU speed, including true mhz + idle skipping mhz

Source/Core/Core/ConfigManager.h

@@ -55,6 +55,7 @@ struct SConfig : NonCopyable
 	bool m_InterfaceStatusbar;
 	bool m_InterfaceLogWindow;
 	bool m_InterfaceLogConfigWindow;
+	bool m_InterfaceExtendedFPSInfo;
 
 	bool m_ListDrives;
 	bool m_ListWad;