Staging: iio: Documentation: Remove unused sysfs attributes

This patch removes the unused sysfs attributes range, range_available,
adc_resolution and adc_resolution_available.
Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/Documentation/sysfs-bus-iio-light

-
-What:		/sys/bus/iio/devices/device[n]/range
-KernelVersion:	2.6.37
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Hardware dependent ADC Full Scale Range used for some ambient
-		light sensors in calculating lux.
-
-What:		/sys/bus/iio/devices/device[n]/range_available
-KernelVersion:	2.6.37
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Hardware dependent supported vales for ADC Full Scale Range.
-
-What:		/sys/bus/iio/devices/device[n]/adc_resolution
-KernelVersion:	2.6.37
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Hardware dependent ADC resolution of the ambient light sensor
-		used in calculating the lux.
-
-What:		/sys/bus/iio/devices/device[n]/adc_resolution_available
-KernelVersion:	2.6.37
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Hardware dependent list of possible values supported for the
-		adc_resolution of the given sensor.
-
 What:		/sys/bus/iio/devices/device[n]/in_illuminance0[_input|_raw]
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org