Unhide the SMBus on the HP xw4100. This gives access to a hardware
monitoring chip (ADT7463) and to the memory module SPD EEPROMs. I
checked that ACPI wasn't accessing the SMBus, so it should be safe.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>