perf counter cleanup (mostly intervals)

Some of these perf counters were useful during initial development, but realistically aren't needed anymore, some are redundant when we can now see the average interval from `work_queue status` and some of them simply aren't worth the cost at higher rates.

src/modules/ekf2/ekf2_main.cpp

@@ -171,8 +171,6 @@ private:
 	uint64_t _start_time_us = 0;		///< system time at EKF start (uSec)
 	int64_t _last_time_slip_us = 0;		///< Last time slip (uSec)
 
-	perf_counter_t _cycle_perf;
-	perf_counter_t _interval_perf;
 	perf_counter_t _ekf_update_perf;
 
 	// Initialise time stamps used to send sensor data to the EKF and for logging
@@ -549,8 +547,6 @@ Ekf2::Ekf2(bool replay_mode):
 	ModuleParams(nullptr),
 	WorkItem(MODULE_NAME, px4::wq_configurations::att_pos_ctrl),
 	_replay_mode(replay_mode),
-	_cycle_perf(perf_alloc_once(PC_ELAPSED, MODULE_NAME": cycle time")),
-	_interval_perf(perf_alloc_once(PC_INTERVAL, MODULE_NAME": interval")),
 	_ekf_update_perf(perf_alloc_once(PC_ELAPSED, MODULE_NAME": update")),
 	_params(_ekf.getParamHandle()),
 	_param_ekf2_min_obs_dt(_params->sensor_interval_min_ms),
@@ -656,8 +652,6 @@ Ekf2::Ekf2(bool replay_mode):
 
 Ekf2::~Ekf2()
 {
-	perf_free(_cycle_perf);
-	perf_free(_interval_perf);
 	perf_free(_ekf_update_perf);
 }
 
@@ -679,8 +673,6 @@ int Ekf2::print_status()
 
 	PX4_INFO("time slip: %" PRId64 " us", _last_time_slip_us);
 
-	perf_print_counter(_cycle_perf);
-	perf_print_counter(_interval_perf);
 	perf_print_counter(_ekf_update_perf);
 
 	return 0;
@@ -728,9 +720,6 @@ void Ekf2::Run()
 		return;
 	}
 
-	perf_begin(_cycle_perf);
-	perf_count(_interval_perf);
-
 	sensor_combined_s sensors;
 
 	if (_sensors_sub.update(&sensors)) {
@@ -1751,8 +1740,6 @@ void Ekf2::Run()
 		// publish ekf2_timestamps
 		_ekf2_timestamps_pub.publish(ekf2_timestamps);
 	}
-
-	perf_end(_cycle_perf);
 }
 
 int Ekf2::getRangeSubIndex()