Bug#790650: autopkgtest: support running adt-virt-qemu without KVM support

[mika@debian.org (Michael Prokop)]

Package: autopkgtest
Version: 3.15.1
Severity: wishlist

adt-virt-qemu has the -enable-kvm option hardcoded, resulting in:

| Could not access KVM kernel module: No such file or directory
| failed to initialize KVM: No such file or directory

when running adt-virt-qemu from inside e.g. a VirtualBox system.
Would be nice if KVM could be disabled somehow.

regards,
-mika-