perf events: Enable raw event support for Intel unhalted_reference_cycles event

This patch adds the encoding and definitions necessary for the
unhalted_reference_cycles event avaialble since Intel Core 2 processors.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-2-git-send-email-eranian@google.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>