This patch supports creation and deletion of portgroups
on multiple distributed switches on vCenter. If user
doesn't provide --provider-physical-network argument, then
portgroup is created on configured DVS in nsx.ini else if
the --provider-physical-network argument is provided with
dvs name in vcenter then portgroup is created on that
distributed virtual switch(DVS).
Change-Id: I0636745835a6f4b0e5fae6e01b6ee754e1d9176d
Closes-Bug: #1714428
d07d4f0d12