toolchain: The glorious return of glibc, ver 2.21

It's the eglibc packaging with a bit of spit-polishing. And testing. :-)

[blogic: merged glibc and eglibc into 1 and made eglibc a glibc variant]

Signed-off-by: Jeff Waugh <jdub@bethesignal.org>
Signed-off-by: John Crispin <blogic@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44701 3c298f89-4303-0410-b956-a3cf2f4a3e73