thermal/drivers/rcar: Use generic thermal_zone_get_trip() function

thermal/drivers/rcar: Use generic thermal_zone_get_trip() function

The thermal framework gives the possibility to register the trip
points with the thermal zone. When that is done, no get_trip_* ops are
needed and they can be removed.

Convert ops content logic into generic trip points and register them with the
thermal zone.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20221003092602.1323944-23-daniel.lezcano@linaro.org