gmtime_r() has been in the minimal libc for years, however it was not
added to expcetions due to an overlook. In order to do this however, it
has to be moved first to the common libc area, so that it's available
to any libc that may not implement it.
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
Introduce a place to share implementations of libc functions that
are needed by different libc versions. Place time() in this common
location so it can be shared when building for either minimal libc or
armclang libc.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>