thermal/core: Fix thermal_cooling_device_register() prototype

There are two pairs of declarations for thermal_cooling_device_register()
and thermal_of_cooling_device_register(), and only one set was changed
in a recent patch, so the other one now causes a compile-time warning:

drivers/net/wireless/mediatek/mt76/mt7915/init.c: In function 'mt7915_thermal_init':
drivers/net/wireless/mediatek/mt76/mt7915/init.c:134:48: error: passing argument 1 of 'thermal_cooling_device_register' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  134 |         cdev = thermal_cooling_device_register(wiphy_name(wiphy), phy,
      |                                                ^~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/mediatek/mt76/mt7915/init.c:7:
include/linux/thermal.h:407:39: note: expected 'char *' but argument is of type 'const char *'
  407 | thermal_cooling_device_register(char *type, void *devdata,
      |                                 ~~~~~~^~~~

Change the dummy helper functions to have the same arguments as the
normal version.

Fixes: f991de5 ("thermal: make device_register's type argument const")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210722090717.1116748-1-arnd@kernel.org

include/linux/thermal.h

@@ -404,12 +404,13 @@ static inline void thermal_zone_device_unregister(
 	struct thermal_zone_device *tz)
 { }
 static inline struct thermal_cooling_device *
-thermal_cooling_device_register(char *type, void *devdata,
+thermal_cooling_device_register(const char *type, void *devdata,
 	const struct thermal_cooling_device_ops *ops)
 { return ERR_PTR(-ENODEV); }
 static inline struct thermal_cooling_device *
 thermal_of_cooling_device_register(struct device_node *np,
-	char *type, void *devdata, const struct thermal_cooling_device_ops *ops)
+	const char *type, void *devdata,
+	const struct thermal_cooling_device_ops *ops)
 { return ERR_PTR(-ENODEV); }
 static inline struct thermal_cooling_device *
 devm_thermal_of_cooling_device_register(struct device *dev,