watchdog: add f71862fg support

Watchdog support for Fintek F71862fg Super-I/O added.
Two different hardware reset pins of the F71862fg chip can be configured 
by an additional module parameter.

Signed-off-by: Lutz Ballaschke <vegan.grindcore@googlemail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>