iio: adc: viperboard_adc: Use devm_iio_device_alloc

Using devm_iio_device_alloc makes code simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
1 file changed