thunderbolt: Add Intel as copyright holder

Intel has done pretty major changes to the driver and we continue to do
so in the future as well. Add Intel as copyright holder of the files we
have done changes.

While there drop "Cactus Ridge" from the headers because this driver
works also with other Thunderbolt controllers.

No functional changes intended.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>