[FIXEDWING] convert gls (gps landing) to a module

conf/firmwares/subsystems/fixedwing/navigation_extra.makefile

@@ -14,6 +14,5 @@ $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/nav_survey_rectangle.c $(SRC_SUBS
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/OSAMNav.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/snav.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/poly_survey_adv.c
-$(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/gls.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/navigation/border_line.c
 

conf/modules/nav_gls.xml

@@ -0,0 +1,18 @@
+<!DOCTYPE module SYSTEM "module.dtd">
+
+<module name="nav_gls" dir="nav">
+  <doc>
+    <description>
+      gps landing system
+ * -automatic calculation of top of decent for const app angle
+ * -smooth intercept posible
+ * -landing direction is set by app fix / also possible in flight!!!
+    </description>
+  </doc>
+  <header>
+    <file name="nav_gls.h"/>
+  </header>
+  <makefile>
+    <file name="nav_gls.c"/>
+  </makefile>
+</module>

sw/airborne/modules/nav/nav_gls.c

@@ -46,7 +46,7 @@
 
 #include "generated/airframe.h"
 #include "state.h"
-#include "subsystems/navigation/gls.h"
+#include "modules/nav/nav_gls.h"
 #include "subsystems/nav.h"
 #include "generated/flight_plan.h"
 

sw/airborne/modules/nav/nav_gls.h

@@ -20,7 +20,7 @@
  */
 
 /**
- * @file subsystems/navigation/gls.h
+ * @file modules/nav/nav_gls.h
  * @brief gps landing system
  */