vswitchd: Make reconfiguration update port configuration again.

vswitchd: Make reconfiguration update port configuration again.

Commit bae7208e91a0 (bridge: Refactor bridge_reconfigure().) introduced
a regression in bridge reconfiguration.  Previously, reconfiguration would
update the configuration of each bridge port, so that if the controller
(or the admin) changed a port's options, then that change would propagate
to the datapath.  Following that commit, that no longer happened.

This commit restores that feature.

Bug #10972.
Reported-by: Michael Hu <mhu@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>