hwmon: (abituguru3) Enable reading from AUX3 fan on Abit AT8 32X

The table for the Abit AT8 32X was incorrectly missing an entry
for the sixth ("AUX3") fan. Add this entry, exporting the fan
reading to userspace.

Closes lm-sensors.org ticket #2339.

Signed-off-by: Alistair John Strachan <alistair@devzero.co.uk>
Tested-by: Daniel Exner <dex@dragonslave.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>