i8k: Stop reading SMM BIOS version during driver probe

This doesn't work on Studio, XPS, Vostro, and Precision laptops,
and it doesn't provide any value except to cause confusion when
it does not work. Drop it and always use DMI BIOS version instead.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>