uclibc: unbreak SH & SPARC

The patch from commit 200aad4f broke sh
and sparc builds.
Add and adjust a patch from uClibc master that fixes this.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>