Wiimote Mapping UI: Motion Input tab: Rework mapping warning, add explanation of and button to open Alternate Input Sources window.

Source/Core/DolphinQt/Config/Mapping/WiimoteEmuMotionControlIMU.h

@@ -25,8 +25,7 @@ private:
   void LoadSettings() override;
   void SaveSettings() override;
   void CreateMainLayout();
-  static QGroupBox* AddWarning(QGroupBox* groupbox);
 
   // Main
-  QHBoxLayout* m_main_layout;
+  QVBoxLayout* m_main_layout;
 };