Add VMI SMP boot hook.  We emulate a regular boot sequence and use the same
APIC IPI initiation, we just poke magic values to load into the CPU state when
the startup IPI is received, rather than having to jump through a real mode
trampoline.

This is all that was needed to get SMP to work.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>