platform/x86:intel/pmc: Discover PMC devices

platform/x86:intel/pmc: Discover PMC devices

On platforms with multiple PMCs, additional PMC devices are discovered
in the SSRAM device associated with the primary PMC. Add support for
discovering PMC devices from SSRAM. Use PMC devid to assign the
corresponding register map.

Signed-off-by: Xi Pardee <xi.pardee@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230613225347.2720665-6-rajvi.jingar@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>