DolphinQt2: Add missing override specifiers

Source/Core/DolphinQt2/Debugger/NewBreakpointDialog.h

@@ -22,7 +22,7 @@ class NewBreakpointDialog : public QDialog
 public:
   explicit NewBreakpointDialog(BreakpointWidget* parent);
 
-  void accept();
+  void accept() override;
 
 private:
   void CreateWidgets();

Source/Core/DolphinQt2/NetPlay/GameListDialog.h

@@ -17,7 +17,7 @@ class GameListDialog : public QDialog
 public:
   explicit GameListDialog(QWidget* parent);
 
-  int exec();
+  int exec() override;
   const QString& GetSelectedUniqueID();
 
 private:

Source/Core/DolphinQt2/NetPlay/PadMappingDialog.h

@@ -20,7 +20,7 @@ class PadMappingDialog : public QDialog
 public:
   explicit PadMappingDialog(QWidget* widget);
 
-  int exec();
+  int exec() override;
 
   PadMappingArray GetGCPadArray();
   PadMappingArray GetWiimoteArray();

Source/Core/DolphinQt2/QtUtils/AspectRatioWidget.h

@@ -13,7 +13,7 @@ class AspectRatioWidget : public QWidget
   Q_OBJECT
 public:
   AspectRatioWidget(QWidget* widget, float width, float height, QWidget* parent = nullptr);
-  void resizeEvent(QResizeEvent* event);
+  void resizeEvent(QResizeEvent* event) override;
 
 private:
   QBoxLayout* m_layout;