drivers: stepper: Fix stepper callbacks when using work_q

Fix issue where stepper callbacks were not being called when
using work_q. This was due to the steps being counted down before
the work_q was rescheduled.

Signed-off-by: Josselin Bunt <josselin@sensible.health>

drivers/stepper/step_dir/step_dir_stepper_common.c

@@ -145,11 +145,11 @@ static void position_mode_task(const struct device *dev)
 		(void)step_dir_stepper_perform_step(dev);
 	}
 
-	update_remaining_steps(dev->data);
-
 	if (config->timing_source->needs_reschedule(dev) && data->step_count != 0) {
 		(void)config->timing_source->start(dev);
 	}
+
+	update_remaining_steps(dev->data);
 }
 
 static void velocity_mode_task(const struct device *dev)