platform/x86/intel/pmc: Enable substate residencies for multiple PMCs

platform/x86/intel/pmc: Enable substate residencies for multiple PMCs

Enable substate residencies support for multiple PMCs. Previously
substate residencies were shown only for the primary PMC. This
change enables substate residencies for all available PMCs.

The output of substate_residencies with this patch will be similar
to this:
pmc0   Substate       Residency
         S0i2.0               0
         S0i2.1               0
         S0i2.2               0
pmc1   Substate       Residency
         S0i2.0               0
         S0i2.1               0
         S0i2.2               0
pmc2   Substate       Residency
         S0i2.0               0

Signed-off-by: Xi Pardee <xi.pardee@linux.intel.com>
Link: https://patch.msgid.link/20260108223144.504267-4-xi.pardee@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>