WioTrackerL1: add joystick left and right for new UI

variants/wio-tracker-l1/target.h

@@ -40,6 +40,8 @@ extern WioTrackerL1SensorManager sensors;
 #ifdef DISPLAY_CLASS
   extern DISPLAY_CLASS display;
   extern MomentaryButton user_btn;
+  extern MomentaryButton joystick_left;
+  extern MomentaryButton joystick_right;
 #endif
 
 bool radio_init();