Fix temperature alarms

Which temperatures generate alarms is not fixed but determined by
the temperature source mapping.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add beep support

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add support for NCT6791D.

Signed-off-by: David Bartley <andareed@gmail.com>