Set the stack size for qurt

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

src/platforms/posix/px4_layer/px4_posix_tasks.cpp

@@ -172,6 +172,14 @@ px4_task_t px4_task_spawn_cmd(const char *name, int scheduler, int priority, int
 		return (rv < 0) ? rv : -rv;
 	}
 
+	rv = pthread_attr_setstacksize(&attr, stack_size);
+
+        if (rv != 0)
+	{
+		PX4_ERR("pthread_attr_setstacksize returned error");
+		return (rv < 0) ? rv : -rv;
+	}
+
 	rv = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
 
 	if (rv != 0) {