* Add APM32F4 driver libraries and USB middleware
* Add the APM32F405 and APM32F407 target files
* Add APM32 startup files
* Add APM32F4 linker files
* Add APM32F4.mk
* Add APM32 driver files
* Add APM32F40X MCU type
* Sync with the Betaflight master branch and modify the driver directory structure
* Implement CLI on the APM32
* Implement ADC on the APM32
* Implement config streamer on the APM32
* Implement I2C on the APM32
* Implement SPI on the APM32
* Implement DSHOT on the APM32
* Implement transponder ir on the APM32
* Implement serial uart on the APM32
* Implement MCO on the APM32
* Implement DWT on the APM32
* Update the init.c file, adding APM32 MCO configuration
* Remove all duplicated APM32 driver files and retaining only the APM32 LIB directory
* Create APM32F4.mk
* Add linker files for APM32F405 and APM32F407
* Add startup and library config files for APM32F405 and APM32F407
* Add target files for APM32F405 and APM32F407
* Add apm32 MCU driver files
* Add build configuration for APM32 MCU
* Implement config streamer on APM32
* Implement CLI on the APM32
* Implement ADC on the APM32
* Implement RCC on the APM32
* Implement MCO on the APM32
* Implement I2C on the APM32
* Implement SPI on the APM32
* Implement serial uart on the APM32
* Implement IO on the APM32
* Implement DMA on the APM32
* Implement DSHOT on the APM32
* Implement transponder ir on the APM32
* Update init.c
* Add the inclusion of the 'platform.h' file to the APM USB driver source file
* Merge bus SPI duplicate code from APM32 to STM32
* Update timer_apm32.c
* Merge motor duplicate code from APM32 to STM32
* Merge serial uart duplicate code from APM32 to STM32
* Update APM32F4.mk
* Update cli.c
* Update APM32F4.mk
* Remove the apm32_flash_f4_split.ld
* Associate the apm32 linker file with stm32_flash_f4_split.ld
When trying to build firmware with current directory in PATH environment
it scans for make command and generates "Permission denied" error in
case if current directory in PATH precedes /usr/bin/ directory.In my
case it was caused by incorrect pyenv init script.
Rename make folder to avoid errors like this.