mc_pos_control limit to 50 Hz

[dagar]

• partially helps with High CPU load on Pixhawk 4 (fmu-v5) #11604

[MaEtUgR]

Based on my past experience with other multicopter flight control software 50Hz update frequency is sufficient for the position control loop and should not impose any performance impact. But we need to test this carefully to make sure there are no side effects in the current implementation.

[Junkim3DR]

Tested on Pixhawk 4 v5; no issues were noted, good flight in general.
https://review.px4.io/plot_app?log=a5db1a1c-644f-43bf-acf5-390844fc685d
Master was tested as well; no noticeable differences.
https://review.px4.io/plot_app?log=c3e08940-4078-466e-aff1-853e28aad108

Tested on Pixhawk 4mini v5; no issues were noted, good flight in general.
https://review.px4.io/plot_app?log=2c918d21-88e7-4932-9ee3-c440b8200646
Master was tested as well; no noticeable differences.
https://review.px4.io/plot_app?log=a6268987-ab5c-4d87-8bbf-e503b30964f1

[jorge789]

Tested on Pixhawk cube v2;
It was tested in all modes Position, Altitude, Stabilized, Mission and RTL and it works very well in all modes.
Note;
It was compared with mater and no noticeable change was seen, but it went well.

FLIGHT (PR11639)
https://review.px4.io/plot_app?log=b5d31c42-f989-485d-846e-d3c3d06138f5

FLIGHT IN MASTER (COMPARISON)
https://review.px4.io/plot_app?log=69241f72-179d-4095-9a32-a22e9c371875

[Tony3dr]

Tested on V2 & V5 no noticeable issues. All flights were successful.