POSIX: added tone_alarm simulator

The tone_alarm simulator was added to rc.S and the warning output for a
hrt_timer with a 0 expiry times was disabled.

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

src/platforms/posix/px4_layer/drv_hrt.c

@@ -301,9 +301,12 @@ hrt_call_internal(struct hrt_call *entry, hrt_abstime deadline, hrt_abstime inte
 	if (entry->deadline != 0)
 		sq_rem(&entry->link, &callout_queue);
 
+#if 0
+	// Use this to debug busy CPU that keeps rescheduling with 0 period time
 	if (interval < HRT_INTERVAL_MIN) {
 		PX4_ERR("hrt_call_internal interval too short: %" PRIu64, interval);
 	}
+#endif
 	entry->deadline = deadline;
 	entry->period = interval;
 	entry->callout = callout;