Add SBUS2 Telemetry support

[mmosca]

This is a port of my INAV code to RotorFlight.

SBUS2 port can be connected to FPORT on rotorflight flight controllers, or on the tx pin of any uart on F7/H7 mcus.

These are the available sensors:

Slot	Sensort Type	Notes
1	Voltage	FC Voltage sensor. Pack and cell voltages
3	Current	FC Current sensor.
6	RPM sensor	Headspeed
7	Temperature	MCU Core temp
8	Kontronic ESC	ESC telemetry data

[rotorflight]

The code in sbus2_sensors.c looks iffy in a few places. Is that your code, or copied from somewhere else?

[rotorflight]

Is this code always sending all sensors once enebled?
Can you choose what sensors are used?

[mmosca]

The code in sbus2_sensors.c looks iffy in a few places. Is that your code, or copied from somewhere else?

That is a copy from https://github.com/BrushlessPower/SBUS2-Telemetry

Not all sensors are used. That is just the code to pack the info in different sensor types.

[mmosca]

Is this code always sending all sensors once enebled? Can you choose what sensors are used?

Only the sensors used in taskSendSbus2Telemetry in sbus2.c are sent.

The sensors used are currently hard coded. The futaba side is a bit limited as some sensors sensors use more than one slot and can only be used in some positions. (Esc, for example, takes a full 8 slot window and can only be on slot 8, 16 or 24).

Different radios also may support a smaller subset of sensors.

[rotorflight]

I am not comfortable about the SBUS task running at 8kHz. It's almost certainly interfering with the gyro task.
We had to drop the gyro task to 1k on F411 and G474, because they could not even run that.
I strongly believe we can't run this either at 8k on those platforms. Probably max 1k.

I think there are two optons here:

1. find another way to guarantee the timing requirements. Increasing the task speed is not the right approach.
2. if it has to run at 8k, enable this feature only on H7

[mmosca]

I am out of town currently. I will run more tests once I am back with hardware access.

[mmosca]

I believe I addreessed all items. Let me know if you need any more changes.

[mmosca]

Tasks output on flydragonf722_v2 with latest changes and lowest priority.

Realtime load reported at ~26-28% and cpu load ~21-22% on configurator status bar, with all features enabled as well as working sbus2 telemetry, If I switch to crsf, instead of sbus2, realtime load, maybe 1% lower ~25-27%, but really hard to call, as it is a bit all over the place in both scenarios.

# tasks
Task list             rate/hz  max/us  avg/us maxload avgload  total/ms   late    run reqd/us
00 - (         SYSTEM)     10       5       1    0.0%    0.0%         1      0      7       4
01 - (         SYSTEM)    993       4       1    0.3%    0.1%       124      1    629       1
02 - (           GYRO)   3231       5       2    1.6%    0.7%       820      0   2044       0
03 - (         FILTER)   3231       5       1    1.6%    0.6%       663      0   2044       0
04 - (            PID)   3231      58      47   18.7%   15.4%     17429      0   2044       0
05 - (            ACC)    798       8       3    0.6%    0.2%       260      0    504       5
06 - (       ATTITUDE)    497      13       7    0.6%    0.3%       444      0    314      10
07 - (             RX)     66      18      12    0.1%    0.0%       290      0    126      17
08 - (         SERIAL)     98    1070       2   10.4%    0.0%        75      0     61     219
09 - (       DISPATCH)    993       7       0    0.6%    0.0%        83      0    629       5
10 - (BATTERY_VOLTAGE)    200       3       2    0.0%    0.0%        57      0    126       3
11 - (BATTERY_CURRENT)    200       1       0    0.0%    0.0%        19      0    126       1
12 - ( BATTERY_ALERTS)      5       2       2    0.0%    0.0%         0      0      3       3
13 - (         BEEPER)     98       2       1    0.0%    0.0%        14      0     61       1
16 - (           BARO)     43      29       6    0.1%    0.0%       103      0     72       8
17 - (      TELEMETRY)    249       3       0    0.0%    0.0%       133      0    156       2
18 - (       LEDSTRIP)     98      17       5    0.1%    0.0%        46      0     61      33
21 - (    ADCINTERNAL)      1       3       3    0.0%    0.0%         0      0      1       8
23 - (SBUS2_TELEMETRY)   6345       6       0    3.8%    0.3%       451      0   3986       3
RX Check Function                   1       0                        12
Total (excluding SERIAL) 

[rotorflight]

Thank you! Merged manually.