[PATCH] consolidate and cleanup profiling code.

[PATCH] consolidate and cleanup profiling code.

Patch from Nikita Danilov <Nikita@Namesys.COM>

this moves functions from identical per-architecture
arch/*/kernel/profile.c into generic kernel/profile.c.  Also, identical
{x86,parisc,ppc64,sparc64}_profile_hook()'s are all replaced by the
single kernel/profile.c:profile_hook(), which is #defined to noop in
include/linux/profile.h if CONFIG_PROFILING is not set.