[PATCH] Fix modular cpuid.ko

With recent change, if CONFIG_HOTPLUG_CPU is disabled,
register_cpu_notifier() is not exported.  And it breaked moduler msr/cpuid
(msr.c was already fixed).

We need to use register_hotcpu_notifier() now in module, instead of
register_cpu_notifier().

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>