toolchain/uClibc: add support of uClibc-ng

toolchain/uClibc: add support of uClibc-ng

uClibc-ng is a spin-off of original uClibc, see http://www.uclibc-ng.org/

We try to regularly add changes from uClibc to uClibc-ng.
We even sent patches and bug reports to the uClibc mailing list.
The config file is compatible between uClibc-ng 1.0 and uClibc git master.
This might change in the future.

Our main goal is to provide regularly a stable and tested release
to make embedded system developers happy.

The main advantage of uClibc-ng over olde good uClibc is regular releases
so there's no need to keep tons of patches on top of years old
0.9.33.2

Build-tested for
 [1] ARM: Sunxi generic
 [2] MIPS: Netgear WNDR3600/3700/3800

Run-tested for [yet out of the tree] Synopsys Designware ARC AXS101.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Waldemar Brodkorb <wbx@uclibc-ng.org>
Cc: Mathieu Olivari <mathieu@codeaurora.org>
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47077 3c298f89-4303-0410-b956-a3cf2f4a3e73