Allow NSX MP and Edge VM IPs to be Set to DHCP

[edwardbadboy]

Currently we have to define static IPs on admin network for NSX Manager ad Edge.
The static IP count is also used to determine the number of MP/Edge appliances to deploy.

I think maybe we can allow the user to use DHCP on these appliances by defining the IPs like this:

nsx_manager_ips: DHCP,DHCP,DHCP
edge_ips: DHCP,DHCP,DHCP

So it still uses the count of items to determine appliance number. Once it finds the value of an item is "DHCP", it can deploy the appliance in DHCP mode.