thermal/drivers/tegra: Fix crash when getting critical temp

Commit 13bea86623be ("thermal/of: Remove of_thermal_get_crit_temp()")
removed the function of_thermal_get_crit_temp() and this is causing a
NULL pointer deference crash when attempting to call the 'get_crit_temp'
function pointer because this function pointer is no longer initialised.
Fix this by replacing the call to the 'get_crit_temp' function pointer
with a call to the function thermal_zone_get_crit_temp() instead.

Fixes: 13bea86623be ("thermal/of: Remove of_thermal_get_crit_temp()")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20221010150311.40384-1-jonathanh@nvidia.comSigned-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/thermal/tegra/soctherm.c

@@ -742,7 +742,7 @@ static int tegra_soctherm_set_hwtrips(struct device *dev,
 	/* Get thermtrips. If missing, try to get critical trips. */
 	temperature = tsensor_group_thermtrip_get(ts, sg->id);
 	if (min_low_temp == temperature)
-		if (tz->ops->get_crit_temp(tz, &temperature))
+		if (thermal_zone_get_crit_temp(tz, &temperature))
 			temperature = max_high_temp;
 
 	ret = thermtrip_program(dev, sg, temperature);