iio: adc: ad9467: change struct members padding

Using tabs and maintaining the start of the variables aligned is a pain and
may lead to lot's of unrelated changes when adding new members. Hence,
let's change things now and just have a simple space.
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240522-dev-ad9467-dma-v2-2-a37bec463632@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>