Revert "Thermal: Introduce thermal_zone_trip_update()"

This reverts commit 3d3fff60945d2812f06a1d17044fffeba26c23f7.
Revert "Thermal: Introduce .get_trend() callback."

This reverts commit ba80c32d4b872af8c5dfd0cfc7f70540a9bdd5ab.