platform/x86: intel_pmc_core: Add CannonLake PCH support

This adds support for Cannonlake PCH which is used by Cannonlake and
Coffeelake SoCs.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>