- 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()
Add small stubs for _times_r and _link_r so that code using times()
or link() can still compile. The functions are marked as not implemented
and return invalid codes.