powercap: intel_rapl: Add support for Gemini Lake

Gemini Lake RAPL support is similar to Goldmont.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Acked-by: Pan, Jacob jun <jacob.jun.pan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>