connector: add portid to unicast in addition to broadcasting

This allows replying only to the requestor portid while still
supporting broadcasting.  Pass 0 to portid for the previous behavior.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>