Add OBattler's hard disk tracking code and make use of it for HDD settings

src/qt/qt_harddrive_common.hpp

@@ -4,10 +4,12 @@
 
 class QString;
 class QAbstractItemModel;
+class SettingsBusTracking;
 
 namespace Harddrives {
     void populateBuses(QAbstractItemModel* model);
     void populateRemovableBuses(QAbstractItemModel* model);
     void populateBusChannels(QAbstractItemModel* model, int bus);
     QString BusChannelName(uint8_t bus, uint8_t channel);
+    inline SettingsBusTracking* busTrackClass = nullptr;
 };