thermal: core: Clean up headers of thermal zone registration functions

For consistency, add a missing thermal_zone_device_register_with_trips()
stub for the CONFIG_THERMAL unset case, specify argument names in all of
the thermal zone registration and unregistration function headers and
make all of them use white space consistently.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>