iio: resistance: Document that resistance can be output

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 8ce14c8..3786863 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1474,6 +1474,8 @@
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistance_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistanceX_raw
+What:		/sys/bus/iio/devices/iio:deviceX/out_resistance_raw
+What:		/sys/bus/iio/devices/iio:deviceX/out_resistanceX_raw
 KernelVersion:	4.3
 Contact:	linux-iio@vger.kernel.org
 Description: