iio: Documentation: Add additional *scale_available attributes

Added some more *scale_available attributes to the list that
are used in various drivers but were missiong from Documentation.

Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/ABI/testing/sysfs-bus-iio

@@ -413,6 +413,11 @@ Description:
 		to compute the calories burnt by the user.
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_accel_scale_available
+What:		/sys/.../iio:deviceX/in_anglvel_scale_available
+What:		/sys/.../iio:deviceX/in_magn_scale_available
+What:		/sys/.../iio:deviceX/in_illuminance_scale_available
+What:		/sys/.../iio:deviceX/in_intensity_scale_available
+What:		/sys/.../iio:deviceX/in_proximity_scale_available
 What:		/sys/.../iio:deviceX/in_voltageX_scale_available
 What:		/sys/.../iio:deviceX/in_voltage-voltage_scale_available
 What:		/sys/.../iio:deviceX/out_voltageX_scale_available