powercap: Add AMD Fam17h RAPL support

Enable AMD Fam17h RAPL support for the power capping framework.

The support is as per AMD Fam17h Model31h (Zen2) and model 00-ffh
(Zen1) PPR.

Tested by comparing the results of following two sysfs entries and the
values directly read from corresponding MSRs via /dev/cpu/[x]/msr:
  /sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj
  /sys/class/powercap/intel-rapl/intel-rapl:0/intel-rapl:0:0/energy_uj

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