x86: Select BUILDTIME_EXTABLE_SORT

We can sort the exeception table at build time for x86, so let's do
it.

Signed-off-by: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1334872799-14589-6-git-send-email-ddaney.cavm@gmail.com


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>