Enhanced the Makefiles to consistently use the BUIDDIR variable.
Slightly optimized all Makefiles
ChibiOS updated to version stable_19.1.x.NOTE: ChibiOS 19.1.x seems to contain some issues as of now.
set the C standard to C17 (ISO), although this does not make any difference according to GCC documentation
Renamed two modules:- STM32L476RG-NUCLEO64 > NUCLEO-L476RG STM32F4Discovery -> STM32F407G-DISC1