This should allow for easier adding of hotplug cpu support for other PPC64
subarchs.  The patch is untested but does compile with and without hotplug
cpu on pSeries and G5 configs.  What can get slightly confusing is the fact
that both ppc_md and smp_ops have cpu_die members.
Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>