hwmon: (dell-smm) Blacklist Dell Studio XPS 8000

Since Linux 4.0 the CPU fan speed is going up and down on Dell Studio
XPS 8000 and 8100 for unknown reasons. The 8100 was already
blacklisted in commit a4b45b25

 ("hwmon: (dell-smm) Blacklist
Dell Studio XPS 8100"). This patch blacklists the XPS 8000.

Without further debugging on the affected machine, it is not possible
to find the problem. For more details see
https://bugzilla.kernel.org/show_bug.cgi?id=100121

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Cc: stable@vger.kernel.org # v4.0+, will need backport
Signed-off-by: Guenter Roeck <linux@roeck-us.net>