Revert "hack to make sim works with airspeed_ets: added sim_ir to sim…

… target because sim_airspeed is set there"

This reverts commit 883ac3e.

conf/modules/airspeed_ets.xml

@@ -22,13 +22,5 @@
     <file name="airspeed_ets.c"/>
   </makefile>
 
-  <!--
-    hack to make sim work,
-    in sim_ir the variable sim_airspeed is set, should be refactored
-  -->
-  <makefile target="sim">
-    <file_arch name="sim_ir.c" dir="."/>
-    <file name="infrared.c" dir="subsystems/sensors"/>
-  </makefile>
 </module>