thermal/of: Remove old OF code

All the drivers are converted to the new OF API, remove the old OF code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linexp.org>
Link: https://lore.kernel.org/r/20220804224349.1926752-34-daniel.lezcano@linexp.org


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>