linux-phytec-ti

staging: iio: ad2s1200: Add copyright

Add David Veenstra as a copyright holders and as an author,
for all of the staging clean ups of the ad2s1200 driver.

Signed-off-by: David Veenstra <davidjulianveenstra@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>