Adds macvtap support

The current logic handles only VFs with direct vnic-type.
This fix will add support for VFs with macvtap vnic-type,
By checking the relevant upper_macvtap directory.

Change-Id: Id69b7e64858020682fd0f68b0e162e5e8022eea3
Closes-Bug: 1383098
Merge "Adds macvtap support"