ACPI: PMIC: allow drivers to provide a custom lpat_raw_to_temp() function

The LPAT tables used in the DSDT for some PMICs require special handling,
allow the PMIC OpRegion drivers to provide an alternative implementation
by adding a lpat_raw_to_temp function pointer to struct pmic_table;
and initialize this to the default acpi_lpat_raw_to_temp function
for all PMICs.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>