platform/x86: intel/pmc: Remove unused param idx from pmc_for_each_mode()

platform/x86: intel/pmc: Remove unused param idx from pmc_for_each_mode()

pmc_for_each_mode() takes i (index) variable name as a parameter but
the loop index is not used by any of the callers. Make the index
variable internal to pmc_for_each_mode().

This also changes the loop logic such that ->lpm_en_modes[] is never
read beyond num_lpm_modes.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240806083047.1562-1-ilpo.jarvinen@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>