buildroot

uclibc: add various upstream patches

Fix some static linking issues for Xtensa/Blackfin.
Optimize the size for non-threaded static binaries and
fix static C/C++ applications when running on the target.
Fix noMMU madvise declarations.

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>