ioctl: register LTTng ioctl

The LTTng 2.0 kernel tracer (stand-alone module package, available at
http://lttng.org

) uses the 0xF6 ioctl range for tracer control and
transport operations.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>