x86, lguest: fix apic_ops build on UP

fix:

  arch/x86/lguest/boot.c:816: error: variable ‘lguest_basic_apic_ops’ has initializer but incomplete type
  arch/x86/lguest/boot.c:817: error: unknown field ‘read’ specified in initializer
 [...]

Signed-off-by: Ingo Molnar <mingo@elte.hu>