platform/x86/intel/pmc: Enable PkgC LTR blocking counter

platform/x86/intel/pmc: Enable PkgC LTR blocking counter

Enable the Package C-state LTR blocking counter in the PMT telemetry
region. This counter records how many times any Package C-state entry
is blocked for the specified reasons.

Add pmc_core_pkgc_counters_show() as a common helper to display
package C-state blocking counters from the telemetry region.

Signed-off-by: Xi Pardee <xi.pardee@linux.intel.com>
Link: https://patch.msgid.link/20260505043342.2573556-3-xi.pardee@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>