Fixes the Hyper-V agent individual ports metrics

Replaces aggregated metric values with separated values for each port.

Co-Authored-By: Adrian Vladu <avladu@cloudbasesolutions.com>

(cherry picked from commit 4559a5f381082dba30bb535b69deeb09135da680)

Change-Id: Ie946dff984ef53f014c6c57f8d1d5bb9c6e7596d
Closes-Bug: #1289007
Merge "Fixes the Hyper-V agent individual ports metrics" into stable/havana
Merge branch 'stable/havana' of https://github.com/openstack/quantum into havana/stable