Qt/debugger: properly updates when we break

The Host_UpdateDisasmDialog was unimplemented in Qt which is required to get updates when we break.  Additionally, this updates the debugger toolbar.

Source/Core/DolphinQt2/Host.h

@@ -33,6 +33,7 @@ signals:
   void RequestStop();
   void RequestRenderSize(int w, int h);
   void UpdateProgressDialog(QString label, int position, int maximum);
+  void UpdateDisasmDialog();
 
 private:
   Host();