ACPI: thermal: Add device list to struct acpi_thermal_trip

The device lists present in struct acpi_thermal_passive and struct
acpi_thermal_active can be located in struct acpi_thermal_trip which
then will allow the same code to be used for handling both the passive
and active trip points, so make that change.

No intentional functional impact.

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