Documentation update for the scx200_acb driver. Hopefully this will
help future users.
References:
[lm-sensors] Support of i2c-nscacb (April, May 2005)
http://lists.lm-sensors.org/pipermail/lm-sensors/2005-April/011756.html
http://lists.lm-sensors.org/pipermail/lm-sensors/2005-May/012043.html
[lm-sensors] making a geode i2c slave driver (April 2006)
http://lists.lm-sensors.org/pipermail/lm-sensors/2006-April/015998.html