thermal: intel: int340x_thermal: Use thermal zone accessor functions

Make int340x_thermal use the dedicated accessor functions for the
thermal zone device object address and the thermal zone type string.

This is requisite for future thermal core improvements.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>