perf_counter, x86: make x86_pmu data a static struct

Instead of using a pointer to reference to the x86 pmu we now have one
single data structure that is initialized at the beginning. This saves
the pointer access when using this memory.

[ Impact: micro-optimization ]

Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-15-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>