i386: hpet assumes boot cpu is 0

I fixed this in x86_64.  Looks like the kind of thing that will break voyager
on i386.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>