Show the bond mode in the NIC details page

Add a property to get the bonding mode and add it to NIC details

Change-Id: Ic535125cf896311bcbaf3a89eafc7d3c2747e4b7
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1029405
Signed-off-by: Ryan Barry <rbarry@redhat.com>