thunderbolt: Do not re-establish XDomain DMA paths automatically

This step is actually not needed. The service drivers themselves will
handle this once they have negotiated the service up and running again
with the remote side. Also dropping this makes it easier to add support
for multiple DMA tunnels over a single XDomain connection.

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