qt: Disable bus channels that are currently in use

src/qt/qt_settingsharddisks.hpp

@@ -13,9 +13,13 @@ class SettingsHarddisks : public QWidget {
 public:
     explicit SettingsHarddisks(QWidget *parent = nullptr);
     ~SettingsHarddisks();
+    void reloadBusChannels();
 
     void save();
 
+signals:
+    void driveChannelChanged();
+
 private slots:
     void on_comboBoxChannel_currentIndexChanged(int index);
     void on_comboBoxSpeed_currentIndexChanged(int index);
@@ -30,6 +34,7 @@ private slots:
 
 private:
     Ui::SettingsHarddisks *ui;
+    void                   enableCurrentlySelectedChannel();
     bool                   buschangeinprogress = false;
 };