This patch is needed for SMBus multiplexing on the Asus Z8NA-D6 board. It
has an ICH10, I've added support for older ICH chips in case someone
needs it, as it was relatively simply to do that.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>