Fix a build warning when CONFIG_MTK_LVTS_THERMAL_DEBUGFS is not set:

drivers/thermal/mediatek/lvts_thermal.c:266:13: warning: 'lvts_debugfs_exit' defined but not used [-Wunused-function]
  266 | static void lvts_debugfs_exit(struct lvts_domain *lvts_td) { }

Fixes: f5f633b18234 ("thermal/drivers/mediatek: Add the Low Voltage Thermal Sensor driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Balsam CHIHI <bchihi@baylibre.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: linux-pm@vger.kernel.org
---
 drivers/thermal/mediatek/lvts_thermal.c |    2 --
 1 file changed, 2 deletions(-)

--- linux-next-20250501.orig/drivers/thermal/mediatek/lvts_thermal.c
+++ linux-next-20250501/drivers/thermal/mediatek/lvts_thermal.c
@@ -263,8 +263,6 @@ static inline int lvts_debugfs_init(stru
 	return 0;
 }
 
-static void lvts_debugfs_exit(struct lvts_domain *lvts_td) { }
-
 #endif
 
 static int lvts_raw_to_temp(u32 raw_temp, int temp_factor)