thunderbolt: Add XDomain UUID exchange support

Currently ICM has been handling XDomain UUID exchange so there was no
need to have it in the driver yet. However, since now we are going to
add the same capabilities to the software connection manager it needs to
be handled properly.

For this reason modify the driver XDomain protocol handling so that if
the remote domain UUID is not filled in the core will query it first and
only then start the normal property exchange flow.

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