iio:trigger: add resource managed (un)register

Add resource managed devm_iio_trigger_register() and
devm_iio_triger_unregister() to automatically clean up registered triggers
allocated by IIO drivers, thus leading to simplified IIO drivers code.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h
index a122bdd..f0890a5 100644
--- a/include/linux/iio/trigger.h
+++ b/include/linux/iio/trigger.h
@@ -125,12 +125,18 @@
  **/
 int iio_trigger_register(struct iio_trigger *trig_info);
 
+int devm_iio_trigger_register(struct device *dev,
+			      struct iio_trigger *trig_info);
+
 /**
  * iio_trigger_unregister() - unregister a trigger from the core
  * @trig_info:	trigger to be unregistered
  **/
 void iio_trigger_unregister(struct iio_trigger *trig_info);
 
+void devm_iio_trigger_unregister(struct device *dev,
+				 struct iio_trigger *trig_info);
+
 /**
  * iio_trigger_set_immutable() - set an immutable trigger on destination
  *