perf_event, x86: Annotate init functions and data

Annotate init functions and data with __init and __initconst.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@gmail.com>
LKML-Reference: <4AFB721E.8070203@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>