Config: Remove Core::DCBZ [bDCBZOFF] - obsolete

This option completely disabled the DCBZ instruction. Users are toggling
this option in dolphin forks and using that same problematic config when
launching dolphin. Removing the option from dolphin will let the config be
ignored.

Source/Core/Core/ConfigManager.h

@@ -122,7 +122,6 @@ struct SConfig
   bool bRunCompareClient = false;
 
   bool bMMU = false;
-  bool bDCBZOFF = false;
   bool bLowDCBZHack = false;
   int iBBDumpPort = 0;
   bool bFastDiscSpeed = false;