Upgrade ovn-kubernetes CNI to latest release

Upgrade ovn-kubernetes CNI to latest release

Upgrade ovn-kubernetes CNI to latest release(the commit id:
ef14b95bafd07c20cf253b165780c5e88241dbfd).

This installation supports both arm64 and amd64
with multi-arched images.

Fix an error in the install-ovn-k8s.sh script.

Add a cleanup action before the installation
to make sure there would be no obsolete
ovs db information to bother the work of current ovs/ovn which
is actually existed and bothered a lot.

Signed-off-by: Trevor Tao <trevor.tao@arm.com>
Change-Id: Ia37f06d795a216979416d70c5fbd44765ce83837
Signed-off-by: Trevor Tao <trevor.tao@arm.com>