Revert "Cisco DFA ML2 Mechanism Driver"

This reverts commit 3680fd61c9a1cceaa011b4d0d37d235abf490c50.

The reverted patch incorrectly ties with Keystone and should have never been
approved since the approved version only partially addressed review concerns.

This revert also ensure migration timeline integrity.

Change-Id: If5fbdade72c762b21a477676ded816ce5be97ca5
Merge "Revert "Cisco DFA ML2 Mechanism Driver""