x86: mach_apicdef.h need to include before smp.h

smp.h internal has include, so need to include that at first
when genericarch use them need to have different apicdef.h

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>