[CentOS] Stop the FUD Xen is not deprecated

[Chan Chung Hang Christopher]

> Xen _hypervisor_ will not make it into the kernel, because there's no point
> in that. It's not part of Xen design.
>
> Linux support for Xen hypervisor is already in Linux kernel.
>   
Whatever. From the last few months of testing with Xen, I really could 
care less about running anything on it.

I like the comfy feeling I get when I see that I have one less place to 
hit for troubleshooting/compromising with the kvm solution.