platform/x86:intel/pmc: Show substate requirement for S0ix blockers

platform/x86:intel/pmc: Show substate requirement for S0ix blockers

Add support to read and show S0ix blocker substate requirements.
Starting from Panther Lake, substate requirement data is provided
based on S0ix blockers instead of all low power mode requirements.
For platforms that support this new feature, add support to display
substate requirements based on S0ix blockers.

Change the "substate_requirements" attribute of Intel PMC Core
driver to show the substate requirements for each S0ix blocker
and the corresponding S0ix blocker value.

Signed-off-by: Xi Pardee <xi.pardee@linux.intel.com>
Link: https://patch.msgid.link/20250910210629.11198-5-xi.pardee@linux.intel.com
[ij: rename pmc_index -> pmc_idx]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>