Impact: clean up

We can autodetect those system that need cluster apic, and update genapic
accordingly.

We can also remove wakeup.h for e7000, because it's default one is now
the same as overall default mach_wakecpu.h
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>