Fix issues observed with the Startech docking station:

Fix the type of the route parameter in tb_ctl_rx. It should be u64 and not
u8 (which only worked for short routes).

A thunderbolt cable contains two lanes. If both endpoints support it a
connection will be established on both lanes. Previously we tried to
scan below both "dual link ports". Use the information extracted from
the drom to only scan behind ports with lane_nr == 0.

Endpoints with more complex thunderbolt controllers have some of their
ports disabled (for example the NHI port or one of the HDMI/DP ports).
Accessing them results in an error so we now ignore ports which are
marked as disabled in the drom.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>