thunderbolt: Add trace events support for the control channel

Sometimes it is useful to see the traffic happening inside the control
channel, especially when debugging a possible problem. This adds
tracepoints close to the hardware which can be enabled dynamically as
needed using the standard Linux trace events facility.

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