The following patch adds support for the LM99 chip to the lm90 driver,
on popular request. The nVidia GeForce FX 5900 series cards have such a
chip on-board for monitoring the GPU temperature.

Relevant pointers:
http://archives.andrew.net.au/lm-sensors/msg07671.html
http://secure.netroedge.com/~lm78/readticket.cgi?ticket=1661
http://secure.netroedge.com/~lm78/readticket.cgi?ticket=1662

Additional effects of the patch:

* Do not consider the lm90 driver experimental anymore. I have had
enough testers and not a single problem report, the driver is working
OK.

* Support the LM89. According to the datasheets, it is exactly the same
chip as the LM99 (to the chip ID). We've never seen this chip in a
computer so far, but it doesn't cost anything to support it (actually we
cannot not support it, since we have no way to differenciate with the
LM99).

* Scan two addresses instead of one. The LM99 and LM89 have a "-1"
variant using an alternate address.

* Update copyright year.

* Reword the identification code a bit. It is hopefully slightly less
unreadable.

This patch was successfully tested by Corey Hickey.