thermal/drivers/rcar_gen3: Use the generic function to get the number of trips

The thermal core framework allows to get the number of thermal trips,
use it instead of visiting the thermal core structure internals.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20221003092602.1323944-16-daniel.lezcano@linaro.org

drivers/thermal/rcar_gen3_thermal.c

@@ -529,7 +529,7 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		if (ret)
 			goto error_unregister;
 
-		ret = of_thermal_get_ntrips(tsc->zone);
+		ret = thermal_zone_get_num_trips(tsc->zone);
 		if (ret < 0)
 			goto error_unregister;