* implement dshot bitbang for AT32
* fix dshot bitbang bidirectional for AT32
* AT32 target features
* implement latest improvements from steve to at32
* generalize AT32 target.h
* Tri-state USART TX output if load due to powered down peripheral is detected
* enable LED STRIP for AT32
* at bitbang timer adjustments
* revert makefile changes
* revert target generalization
* Update src/main/drivers/at32/platform_mcu.h
Co-authored-by: Mark Haslinghuis <mark@numloq.nl>
---------
Co-authored-by: Steve Evans <Steve@SCEvans.com>
Co-authored-by: J Blackman <blckmn@users.noreply.github.com>
Co-authored-by: Mark Haslinghuis <mark@numloq.nl>