thunderbolt: Create multiple DisplayPort tunnels if there are more DP IN/OUT pairs

Currently we only create one DisplayPort tunnel even if there would be
more DP IN/OUT pairs available. Specifically this happens when a router
is unplugged and we check if a new DisplayPort tunnel can be created. To
cover this create tunnels as long as we find suitable DP IN/OUT pairs.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>