Implementation of Virtual Com Port (composite USB) and DSHOT motor signal protocol

[tobbeanton]

This is a pretty hefty PR but it was hard to break it down...

• ST USB device driver updated to V2.2.1
• Virtual com port (VCP) has been implemented alongside the Crazyflie interface making a composite USB device.
• VCP is used to support BLHeli 4-way passthough interface. Works with the BLHeliConfiguratior for windows (in wine in linux).
• DSHOT implementation for CF2.1-BL prototype and Bolt 1.1
• 4way protocol and logic adapted from Betaflight.
• FreeRTOS task notifications enabled and used for 4-wire interface.
• 4way task created with max priority since the half-duplex uart protocol used (AVRootloader) to communicate with the ESCs is bit-banged.
• Crazyflie 2.1 Brushless config added to Crazyflie platform.

Documentation is still lacking and will be made when things are a bit more clear and figured out as part of getting Bolt out of early access.

The crazyflie-lib-python cfusb driver needs to be new for the cfclient to be able to connect using USB.

[knmcguire]

I'm getting a build error for the cfbl.

make cfbl_defconfig
make -j16

Results in this error:

../src/drivers/src/motors.c: In function 'motorsPrepareDshot':
../src/drivers/src/motors.c:403:5: error: 'dmaWait' undeclared (first use in this function)
  403 |     dmaWait++;
      |     ^~~~~~~
../src/drivers/src/motors.c:403:5: note: each undeclared identifier is reported only once for each function it appears in
../src/drivers/src/motors.c: At top level:
cc1: error: unrecognized command line option '-Wno-stringop-overread' [-Werror]
cc1: all warnings being treated as errors
make[4]: *** [../scripts/Makefile.build:190: src/drivers/src/motors.o] Error 1
make[3]: *** [../scripts/Makefile.build:311: src/drivers/src] Error 2
make[2]: *** [../scripts/Makefile.build:311: src/drivers] Error 2
make[2]: *** Waiting for unfinished jobs....

The CI doesn't use this config yet so that is why it didn't catch this

[knmcguire]

It's a lot... and I won't be able to review it all, for the communication part @evoggy is probably the best.

Maybe we need to do release testing width for the size of this PR

[knmcguire]

the configfile is called cfbl_defconfig eventhough the platform calls it cf21b. Should we try to uniform it somehow?

[knmcguire]

typo: Warning