perf events: Add Intel x86 mapping for PERF_COUNT_HW_REF_CPU_CYCLES

Add event maps for Intel x86 processors (with architected PMU v2 or later).

On AMD, there is frequency scaling but no Turbo. There is no core
cycle event not subject to frequency scaling, therefore we do not
provide a mapping.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-4-git-send-email-eranian@google.comSigned-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perf_event_intel.c

@@ -28,6 +28,7 @@ static u64 intel_perfmon_event_map[PERF_COUNT_HW_MAX] __read_mostly =
   [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= 0x00c4,
   [PERF_COUNT_HW_BRANCH_MISSES]		= 0x00c5,
   [PERF_COUNT_HW_BUS_CYCLES]		= 0x013c,
+  [PERF_COUNT_HW_REF_CPU_CYCLES]	= 0x0300, /* pseudo-encoding */
 };
 
 static struct event_constraint intel_core_event_constraints[] __read_mostly =