Impact: fix boot crash on 32-bit

Hiroshi Shimamoto reported a boot failure on 32-bit x86.

The setting of x86_quirks.wakeup_cpu is missing (when
not passing in an explicit apic= boot parameter).
Reported-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>