I've confirmed that monitoring the package power usage as well as setting power
limits appear to be working as expected. Supports the package and dram domains.

Tested aginst cpu:

Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz
Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>