thermal/drivers/hisi: Change the platform data pointer to sensor ops

Group the temperature sensor specific ops into a single structure and
assign it to hisi thermal data structure.

Change the platform data pointer to reference the specific sensor ops
instead of the probe functions.

Moving out those allow to split the code to self-encapsulate the
sensor object.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>