rocker: set FDB cleanup timer according to lowest ageing time

rocker: set FDB cleanup timer according to lowest ageing time

[ Upstream commit 88de1cd457e5cb664d6d437e2ea4750d089165f5 ]

In rocker, ageing time is a per-port attribute, so the next time the FDB
cleanup timer fires should be set according to the lowest ageing time.

This will later allow us to delete the BR_MIN_AGEING_TIME macro, which was
added to guarantee minimum ageing time in the bridge layer, thereby breaking
existing behavior.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>