iio: electricalconductivity: add IIO_ELECTRICALCONDUCTIVITY type

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
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 df44998..e7f590c 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1565,3 +1565,10 @@
 		* X is in the plane of the propellers, perpendicular to Y axis,
 		  and positive towards the starboard side of the UAV ;
 		* Z is perpendicular to propellers plane and positive upwards.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_electricalconductivity_raw
+KernelVersion:	4.8
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Raw (unscaled no offset etc.) electric conductivity reading that
+		can be processed to siemens per meter.