Port  API Test Enhancement

Add a test to create a port with user defined  mac address
    -Create a port to get a ideal mac
    -Delete the created port
    -Create a port with user defined mac address
    -Validate the mac address after port creation

Change-Id: Icfdf3539cb213cdf77408c8d92c09d9fc95b6eee
Merge "Port  API Test Enhancement"