powercap / RAPL: Support Knights Landing

This patch enables intel_rapl driver to run on the
next-generation Intel(R) Xeon Phi Microarchitecture
code named "Knights Landing"

Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>