log irlock_report and landing_target_pose messages

Need to log both, because on some systems the
information will come in directly as a 
landing_target_pose message, and on others
it's coming in as irlock_report and then filtered
in PX4 to produce the landing_target_pose message.

src/modules/logger/logged_topics.cpp

@@ -62,7 +62,7 @@ void LoggedTopics::add_default_topics()
 	add_topic("cpuload");
 	add_optional_topic("esc_status", 250);
 	add_topic("failure_detector_status", 100);
-	add_topic("follow_target", 500);
+	add_optional_topic("follow_target", 500);
 	add_optional_topic("generator_status");
 	add_optional_topic("gps_dump");
 	add_optional_topic("heater_status");
@@ -70,6 +70,8 @@ void LoggedTopics::add_default_topics()
 	add_topic("hover_thrust_estimate", 100);
 	add_topic("input_rc", 500);
 	add_optional_topic("internal_combustion_engine_status", 10);
+	add_optional_topic("irlock_report", 1000);
+	add_optional_topic("landing_target_pose", 1000);
 	add_optional_topic("magnetometer_bias_estimate", 200);
 	add_topic("manual_control_setpoint", 200);
 	add_topic("manual_control_switches");