platform/x86/intel/pmc: Cleanup SSRAM discovery

platform/x86/intel/pmc: Cleanup SSRAM discovery

Clean up the code handling SSRAM discovery. Handle all resource allocation
and cleanup in pmc_core_ssram_get_pmc(). Return the error status from this
function but only fail the init if we fail to discover the primary PMC.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231129222132.2331261-14-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>