platform/x86: intel_pmc_core: Handle sub-states generically

platform/x86: intel_pmc_core: Handle sub-states generically

The current implementation of pmc_core_substate_res_show() is written
specifically for Tiger Lake. However, new platform will also have
sub-states and may support different modes. Therefore rewrite the code to
handle sub-states generically.

Obtain the number and type of enabled states form the PMC. Use the Low
Power Mode (LPM) priority register to store the states in order from
shallowest to deepest for displays. Add a for_each macro to simplify
this. While changing the sub-state display it makes sense to show only the
"enabled" sub-states instead of showing all possible ones. After this
patch, the debugfs file looks like this:

Substate   Residency
S0i2.0     0
S0i3.0     0
S0i2.1     9329279
S0i3.1     0
S0i3.2     0

Suggested-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Link: https://lore.kernel.org/r/20210417031252.3020837-4-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>