macvlan: Support bonding events

Bonding and team drivers generate specific events during failover
that trigger switch updates.  When a macvlan device is configured
on top of bonding, we want switches to learn about the macvlan
devices as well.   This patch adds a handler to macvlan driver to
propagate these events to all macvlan devices.  We let the generic
inetdev event handler do the work.

This allows macvlan to operated correctly over active-backup
mode bond.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>