perf/x86: Fix event constraint for SandyBridge-EP C-Box

The constraint for C-Box event 0x1f should have overlap flag set.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340866596-22502-2-git-send-email-zheng.z.yan@intel.com


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