Add tests for Nova SR-IOV cold migrate

Logic for testing are the same as for test_cold_migration,
but server are created witn SR-IOV neuron port.
Test are available if the following config variables are set:

[compute]
min_compute_nodes = 2
fixed_network_name = <network>

[compute-feature-enabled]
sriov_cold_migration = true

Change-Id: Ia6fe4cd4a4f12b71a532cfcded20b8f9098c42b2
PROD: https://mirantis.jira.com/browse/PROD-17425,PROD-18630
(cherry picked from commit 7f3a7b520680b2a33aeb2245abf2bf525cd17dfe)
2 files changed