hwmon: (ntc_thermistor) Fix temperature type reporting

Commit 7cc7de93 ("hwmon: (ntc_thermistor) Convert to new hwmon API")
converted the driver to use the new hwmon API, but introduced a subtle
error: The temperature type is no longer reported as temp1_type, but as
temp2_type.

Fixes: 7cc7de93 ("hwmon: (ntc_thermistor) Convert to new hwmon API")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>