Disable kvm on OVH infra instances

OVH infra hosts are causing "KVM: entry failed, hardware error 0x0"
failures where instances fail to start (cirros, etc.).
This patch excludes OVH instances from kvm enablement until the issue is
resolved.

Change-Id: I50006cb60deef6943d95c2c04c444dccca94c8b0
1 file changed