[CentOS] intel_iommu=on => No root device found

> Try booting the system without intel_iommu=on, but with the IOMMU 
> enabled in the bios.  Something has to be at 05:01.0.  Do you see any 
> Ricoh devices anywhere in lspci output?

That's exactly what I did.

I uploaded the full output of `lspci -vv`: http://nilscaspar.ch/centos-lspci.txt

Cheers,
Nils