perf/x86: Enable Intel Cedarview Atom suppport

This patch enables perf_events support for Intel Cedarview
Atom (model 54) processors. Support includes PEBS and LBR.
Tested on my Atom N2600 netbook.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120820092421.GA11284@quad


Signed-off-by: Ingo Molnar <mingo@kernel.org>