- Removed stdio_init() from newlib's _init(), as this is too late in the boot
process to allow DEBUG()ing during periph_init()
- Added stdio_init() to the various cpu_init() routines of the ARM CPUs just
before periph_init()
- With this PR, On start up all GPIOs are configured as AIN. For stm32l0/4
this is done by default. Doing this saves the consumption of the input Schmitt
trigger in STOP mode which can reduce the consumption in at least 70%
from current master.
