hwmon: (w83627hf) Fix setting fan min right after driver load

We need to read the fan clock dividers at initialization time,
otherwise the code in store_fan_min() may use uninitialized values.
That's pretty much the same bug and same fix as for the w83627ehf
driver last month.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>