There are two possibilities: 1. A "integrated-only" option exists and is simply hidden. 2. Such an option was never coded into the BIOS in the first place. It might be possible to work around a hidden menu using methods similar to the VT enabling hack, but if the option was never there I don't think you can just code it in.
Any idea as to how to unhide the option if it's there? Or even just see what's hidden and work from there?
Sorry to bump, but I'm waiting for someone with a better understanding of InsydeH2O to offer some insight.