ACPI: thermal: Collapse trip devices update function wrappers

In order to reduce code duplicationeve further, merge
acpi_thermal_update_passive/active_devices() into one function
called acpi_thermal_update_trip_devices() that will be used for
updating both the passive and active trip points.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>