bridge: Use STP demux

Use the STP demux layer for receiving STP PDUs instead of directly
registering with LLC.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/bridge/Kconfig
Simple merge

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

diff --cc net/bridge/br_private.h
Simple merge

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