uclibc: add libgcc_s_resume fix

This commit adds a fix for building uClibc 0.9.33.2 and uClibc-ng
1.0.3 with gcc 5.1 on ARM, since we're about to add support for gcc
5.1.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>