thunderbolt: Disable CL states when a DMA tunnel is established

Tunnels between hosts should not have CL states enabled because
otherwise they might enter a low power state without the other end
noticing which causes packets to be lost. For this reason disable all
CL states upon first DMA tunnel creation. Once the last DMA tunnel is
torn down we try to re-enable them.

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