bridge: add notification over netlink when STP changes state

When STP changes state of interface need to send a new link
message to reflect that change.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/bridge/br_netlink.c
Simple merge

diff --cc net/bridge/br_stp.c
Simple merge

diff --cc net/bridge/br_stp_if.c
Simple merge

diff --cc net/bridge/br_stp_timer.c
Simple merge