i8k: Add Dell Vostro systems

This trivial patch adds support for i8k on the new Dell Vostro models.
I tested it on my Vostro 1400, and it works. It does print a warning
when loading the module:

	i8k: unable to get SMM BIOS version

But I couldn't figure out how to fix that. The module seems to work fine,
anyway...

Signed-off-by: Federico Heinz <fheinz@vialibre.org.ar>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>