There's xsetup if you want to configure yours. I think the hardware reports what it supports though, or else X wouldn't launch, but I'm not sure. I'm not sure whether or not trying to autoprobe for what seems to be a hardware implementation problem is a good idea. You can load xorg and configure that like in your other thread if you'd like to.
Perhaps setting the default depth to 24 is a good idea anyways, since I don't think 32 is really used.