libc/uClibc: workaround for a MIPS TLS issue

Some macros declarations were missing, so we duplicate them.
See the added patch description for more information.

----> THIS IS A DIRTY HACK! <----

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

reporter_name="Thomas Petazzoni"

reporter_url="http://www.free-electrons.com/"

reporter_comment="Very basic testing only"