Add release notes for the deprecation of a number of POSIX
Kconfig options. These have been deprecated so that we can
use more normative Kconfig variable identifiers, based on
the Options and Option Groups of IEEE 1003.1-2017.
To simplify migration, use
python $ZEPHYR_BASE/scripts/utils/migrate_posix_kconfigs.py \
-r root_path
Additionally, document the removal of PTHREAD_BARRIER_DEFINE(),
EFD_IN_USE, EFD_FLAGS_SET, which were previously deprecated
>= 2 release cycles before.
Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>
