hwmon: (w83795) Fix fan control mode attributes

There were two bugs:
* Speed cruise mode was improperly reported for all fans but fan1.
* Fan control method (PWM vs. DC) was mixed with the control mode.
  It will be added back as a separate attribute, as per the standard
  sysfs interface.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>