Reverted: Use OS independent API for task creation/deletion

Keep existing API use in code. Bind the use of the OS independent
implementation in the systemlib layer.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/drivers/hil/hil.cpp

@@ -48,7 +48,7 @@
  * driver. Use instead the normal FMU or IO driver.
  */
 
-#include <px4_tasks.h>
+#include <nuttx/config.h>
 
 #include <sys/types.h>
 #include <stdint.h>
@@ -188,7 +188,7 @@ HIL::~HIL()
 
 			/* if we have given up, kill it */
 			if (--i == 0) {
-				px4_task_delete(_task);
+				task_delete(_task);
 				break;
 			}
 
@@ -228,7 +228,7 @@ HIL::init()
 	// gpio_reset();
 
 	/* start the HIL interface task */
-	_task = px4_task_spawn_cmd("fmuhil",
+	_task = task_spawn_cmd("fmuhil",
 			   SCHED_DEFAULT,
 			   SCHED_PRIORITY_DEFAULT,
 			   1200,