thermal: core: Add notifications call in the framework

The generic netlink protocol is implemented but the different
notification functions are not yet connected to the core code.

These changes add the notification calls in the different
corresponding places.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200706105538.2159-4-daniel.lezcano@linaro.org