intel_th: Document output device callbacks

'output' type device callbacks are missing from the kerneldoc description
of the 'intel_th_driver' structure. Fix this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index 0df22e3..20f57aa 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -114,6 +114,9 @@
  * @unassign:	deassociate an output type device from an output port
  * @enable:	enable tracing for a given output device
  * @disable:	disable tracing for a given output device
+ * @irq:	interrupt callback
+ * @activate:	enable tracing on the output's side
+ * @deactivate:	disable tracing on the output's side
  * @fops:	file operations for device nodes
  * @attr_group:	attributes provided by the driver
  *