iio: Add blank lines after declarations.

As reported by checkpatch.pl add blank lines after declarations.

Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220727181855.589052-2-joetalbott@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>