hwmon: (jc42) Don't reset hysteresis on device removal

Restoring the configuration register on device removal has the side
effect of also resetting the hysteresis value. This is inconsistent as
the other limits are not reset, only hysteresis. So, following the
principle of least surprise, preserve the hysteresis value when
restoring the configuration register.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>