buildroot

package/autoconf-archive: bump to version v2015.02.24

Fix the AX_CXX_COMPILE_STDCXX_11 macro which was broken in the
previous release.

Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>