Update to 2.6.13pre84 (bz 1674924).
Also:
- Drop the -selinux patch and subpackage, no longer needed.
- Build with -fwrapv.
- Add the -libselinux patch to fix FTBFS if selinuxfs is mounted read-only.
- Build with -mno-pltseq on ppc64le to handle relocation issues.