thermal: intel: intel_pch: Use generic trip points

The thermal framework gives the possibility to register the trip
points along with the thermal zone.  When that is done, no get_trip_*
callbacks are needed and they can be removed.

Convert the existing callbacks content logic into generic trip points
initialization code and register them along with the thermal zone.

In order to consolidate the code, use an ACPI trip library function
to populate a generic trip point.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject and changelog edits, rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>