x86: Add x86_init platform override to fix up NUMA core numbering

Add an x86_init vector for handling inconsistent core numbering.
This is useful for multi-fabric platforms, such as Numascale
NumaConnect.

v2:
 - use struct x86_cpuinit_ops
 - provide default fall-back function to warn

Signed-off-by: Daniel J Blueman <daniel@numascale-asia.com>
Cc: Steffen Persvold <sp@numascale.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Link: http://lkml.kernel.org/r/1323073238-32686-2-git-send-email-daniel@numascale-asia.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>