drivers/thermal/devfreq_cooling: Extend the devfreq_cooling_device with ops

Remove unneeded global variable devfreq_cooling_ops which is used only
as a copy pattern. Instead, extend the struct devfreq_cooling_device with
the needed ops structure. This also simplifies the allocation/free code
during the setup/cleanup.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20220613124327.30766-5-lukasz.luba@arm.com


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