As of previous commit, the CH driver checks for /dev/kvm and/or
/dev/mshv presence. In order to make chxml2xmltest work
regardless of host configuration, introduce a mock that pretends
both of these files are accessible.
Fixes: 51c14df967
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>