tests, sriov: Extend SR-IOV node validation
tests, sriov: Extend SR-IOV node validation

Current SR-IOV node check requires that at least one node supports
SR-IOV.

This change extends the check with an inputted expected count of such
nodes. This addition is useful for tests which require at least 2 such
nodes (e.g. for migration tests).

Signed-off-by: Edward Haas <416ab6a6c3e37a8cab0d365516e79cce8f9be5ad@redhat.com>

stu-gott/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt