x86/Voyager: make it build and boot

[
  mingo@elte.hu: these fixes are a subset of changes cherry-picked from:

     git://git.kernel.org:/pub/scm/linux/kernel/git/jejb/voyager-2.6.git

  They fix various problems that recent x86 changes caused in the Voyager
  subarchitecture: both APIC changes and cpumask changes and certain
  cleanups caused subarch assumptions to break.

  Most of these changes are obsolete as the subarch code has been removed
  from the x86 development tree - but we merge them upstream to make Voyager
  build and boot.
]

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>