powercap: RAPL: Add AMD Fam19h RAPL support

AMD Family 19h's RAPL MSRs are identical to Family 17h's.  Extend
Family 17h's support to Family 19h.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Victor Ding <victording@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>