Add include guard in headers files (#8108)

Signed-off-by: Sugnan Prabhu S <sugnan.prabhu.s@intel.com>

src/modules/position_estimator_inav/inertial_filter.h

@@ -5,6 +5,8 @@
  *   Author: 	Anton Babushkin	<rk3dov@gmail.com>
  */
 
+#pragma once
+
 #include <stdbool.h>
 #include <drivers/drv_hrt.h>
 

src/modules/position_estimator_inav/position_estimator_inav_params.h

@@ -39,6 +39,8 @@
  * Parameters definition for position_estimator_inav
  */
 
+#pragma once
+
 #include <systemlib/param/param.h>
 
 struct position_estimator_inav_params {