To support SRIOV LAG, the driver cannot allow changes to an interface's DCB
configuration when in a bond.  This would break the ability to modify
interfaces Tx scheduling for fail-over interfaces.

Block kernel generated DCB config events when in a bond.
Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>