thermal: Constify 'type' argument for the registration routine

thermal_zone_device_register() does not modify 'type' argument, so it is
safe to declare it as const. Otherwise, if we pass a const string, we are
getting the ugly warning:

CC drivers/power/power_supply_core.o
drivers/power/power_supply_core.c: In function 'psy_register_thermal':
drivers/power/power_supply_core.c:204:6: warning: passing argument 1 of 'thermal_zone_device_register' discards 'const' qualifier from pointer target type [enabled by default]
include/linux/thermal.h:140:29: note: expected 'char *' but argument is of type 'const char *'
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jean Delvare <khali@linux-fr.org>

drivers/thermal/thermal_sys.c

@@ -1173,7 +1173,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
  * longer needed. The passive cooling formula uses tc1 and tc2 as described in
  * section 11.1.5.1 of the ACPI specification 3.0.
  */
-struct thermal_zone_device *thermal_zone_device_register(char *type,
+struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int trips, int mask, void *devdata,
 	const struct thermal_zone_device_ops *ops,
 	int tc1, int tc2, int passive_delay, int polling_delay)

include/linux/thermal.h

@@ -146,7 +146,7 @@ enum {
 };
 #define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)
 
-struct thermal_zone_device *thermal_zone_device_register(char *, int, int,
+struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
 		void *, const struct thermal_zone_device_ops *, int tc1,
 		int tc2, int passive_freq, int polling_freq);
 void thermal_zone_device_unregister(struct thermal_zone_device *);