Migrate configurability from oe, try to shrink minimal image size
All eglibc configuration options are included in conf/distro/include/default-distrovars.inc.
Define DISTRO_FEATURES_LIBC and DISTRO_FEATURES in local.conf with the same way
in local.conf.sample.extended to enable those options.
(From OE-Core rev: 022ca1d1357caafdfe23aa9ab82f90ba89b6942b)
Signed-off-by: Kang Kai <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>