handling ir_top in HITL

sw/airborne/datalink.c

@@ -119,6 +119,9 @@ void dl_parse_msg(void) {
     /** This code simulates infrared.c:ir_update() */
     ir_roll = DL_HITL_INFRARED_roll(dl_buffer);
     ir_pitch = DL_HITL_INFRARED_pitch(dl_buffer);
+#ifdef ADC_CHANNEL_IR_TOP
+    ir_top = DL_HITL_INFRARED_top(dl_buffer);
+#endif // else ir_top is constant
   } else if (msg_id == DL_HITL_UBX) {
     /** This code simulates gps_ubx.c:parse_ubx() */
     if (gps_msg_received) {