* [Core] Fix RISC-V toolchain installation
The risc-v toolchain is only available on distributions based on Debian 11+
so we check for their availability before installing them.
* [Core] Fix heap symbols and syscalls for picolibc
picolibc internally uses __heap_start and __heap_end instead of the
defacto chibios linker script standard __heap_base__ and __heap_end__
therefore we introduce these symbols as an alias. Usually all memory
used within QMK is statically allocated, but some algorithms make usage
of malloc and friends.
Also the timeval struct is not defined by picolibc for syscalls, therefore it
is declared as stub.
* Add support for RISC-V builds and GD32VF103 MCU
* Add toolchain selection in chibios.mk based on the mcu selected in
mcu_selection.mk
* Reorder and added comments to chibios.mk to have a streamlined makefile
* Add GD32VF103 mcu to possible targets for QMK.
* Add STM32 compatibility for GD32VF103 MCU, this is hacky but more efficent
then rewriting every driver.
* Add GigaDevice DFU bootloader as flash target, please note that
dfu-util of at least version 0.10 is needed.
* Add analog driver compatibility
* Add apa102 bitbang driver compatibility
* Add ws2812 bitbang driver compatibility
* Add eeprom in flash emulation compatibility
* Allow faster re-builds with ccache
* Add SiPeed Longan Nano to platform files
* Add SiPeed Longan Nano Onekeys
* Make quine compatible with other bootloaders
* Support builds with picolibc
* Add risc-v toolchain to arch and debian/ubuntu scripts