perf/x86/intel: Add perf core PMU support for Intel Knights Landing

perf/x86/intel: Add perf core PMU support for Intel Knights Landing

Knights Landing core is based on Silvermont core with several differences.
Like Silvermont, Knights Landing has 8 pairs of LBR MSRs. However, the
LBR MSRs addresses match those of the Xeon cores' first 8 pairs of LBR MSRs
Unlike Silvermont, Knights Landing supports hyperthreading. Knights Landing
offcore response events config register mask is different from that of the
Silvermont.

This patch was developed based on a patch from Andi Kleen.

For more details, please refer to the public document:

  https://software.intel.com/sites/default/files/managed/15/8d/IntelXeonPhi%E2%84%A2x200ProcessorPerformanceMonitoringReferenceManual_Volume1_Registers_v0%206.pdf

Signed-off-by: Harish Chegondi <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Harish Chegondi <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Lukasz Anaczkowski <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Link: http://lkml.kernel.org/r/d14593c7311f78c93c9cf6b006be843777c5ad5c.1449517401.git.harish.chegondi@intel.com
Signed-off-by: Ingo Molnar <[email protected]>