defaults: Set sane bond options

Previously no default bond options were set, this could lead to network
connection issues. To prevent this some sane defaults are set if no
other options are given at all.

Change-Id: Id7e1fe9d9773fff79e23593d209bbf68f878cc24
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=996120
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>