Fix multicast enable on the bonded interface

Multicast enable flag should be set when the bonded interface is up.
This flag allows multicast packets to be processed from the slave devices
of the bonded interface. Also promiscuous mode for all-multicast should
be correctly displayed as part of 'show hardware detail' output.

Change-Id: Ief0157c4c030a28afb9c45ebf3d6a12710083724
Signed-off-by: Steve Shin <jonshin@cisco.com>