uclibc: add Thumb2 fixes

This commit adds three patches to uClibc that are needed to make
Thumb2 support work properly:

 uclibc-0006-arm-clone-restore-stack-pointer-just-after-return-fr.patch
 uclibc-0007-arm-clone.S-Add-missing-IT-instruction-for-Thumb2.patch
 uclibc-0008-arm-move-check-for-BX-to-its-own-header.patch

The first one is a necessary dependency of the second one. Both of
those patches have already been merged upstream, after 0.9.33.2. The
third one hasn't been merged upstream yet, but it has already been
submitted a while ago by Yann E. Morin, without receiving attention
from upstream.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>