* TIM/DMA abstraction
* Migrage F7 TIM/DMA to HAL_LL
* Refactor timers to use conventional HZ
* Refactor PWM ourput code to use highest possible resolution
* Remove TIMER_OUTPUT_ENABLED
* Temporary disable SPRACINGF3NEO due to out of RAM
Split INVERTER_PIN_UART<n> into INVERTER_PIN_UART<n>_RX and
INVERTER_PIN_UART<n>_TX. This allows us to invert just one line
of the port in F4 based controllers, like we can do on F3.
Fixes#3466
* Initial cut on cleaning up makefile and libraries.
* F3, F4, F7 support
* Add 'make release' to build targets for release
* Introduce BUILD_SUFFIX options; Comment fix
* Fix USB core
* Fix F7 warnings
* Clean up STM32F1 code
* More cleanups of unused files