package/uclibc: libm: Add missing C99 float/ld wrappers (backport)

This commit adds a patch to uclibc with a backport from upstream to provide a
proper fix for mesa3d which depends on fminf.

As discussed with Thomas we keep the mesa3d patch around for a while:
http://lists.busybox.net/pipermail/buildroot/2015-March/123410.html



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>