[PATCH] mark init_amd() as __cpuinit

The init_amd() function is only called from identify_cpu() which is already
marked as __cpuinit. So let's mark it as __cpuinit.

Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>