bond: 1 packet/frame == bad performance [VPP-1236]
bond: 1 packet/frame == bad performance [VPP-1236]

While https://gerrit.fd.io/r/#/c/11316/ took care of 1 packet/frame for
most of the bonding modes, it missed the broadcast mode. This patch is
to fix the 1 packet/frame for the broadcast mode.

Change-Id: Iac48a2977c7f702f341479cc712a6448090dbc60
Signed-off-by: Steven <a748ea44ad7b179c2313a856d44e1e4eb39869bb@cisco.com>

FDio/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp