Use event loop time in aos/controls/control_loop

Otherwise we can get lost when mixing up times.

Change-Id: I0920341d0b7a7fda8bd70d377d256f0260a50d84
diff --git a/aos/controls/control_loop-tmpl.h b/aos/controls/control_loop-tmpl.h
index 49bad45..2b57a0b 100644
--- a/aos/controls/control_loop-tmpl.h
+++ b/aos/controls/control_loop-tmpl.h
@@ -83,8 +83,9 @@
     }
   }
 
-  const ::aos::monotonic_clock::time_point now = ::aos::monotonic_clock::now();
-  const bool motors_off = now >= kPwmDisableTime + last_pwm_sent_;
+  const ::aos::monotonic_clock::time_point monotonic_now =
+      event_loop_->monotonic_now();
+  const bool motors_off = monotonic_now >= kPwmDisableTime + last_pwm_sent_;
   joystick_state_fetcher_.Fetch();
   if (motors_off) {
     if (joystick_state_fetcher_.get() && joystick_state_fetcher_->enabled) {