[PATCH] hwmon: w83792d fix unused fan pins

1. This patch add check for fan4,5,6,7 and do not create device file
   if their pins are not configured as fan.
2. Fix the issue that can not set fan divisor to 128.
3. Fix the index out of bounds bug in w83792d_detect function.

Signed-off-by: Yuan Mu <ymu@winbond.com.tw>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>