ABI: obsolete/sysfs-bus-iio: add some missing blank lines

Avoid those warnings:
	Documentation/ABI/obsolete/sysfs-bus-iio:171: WARNING: Unexpected indentation.
	Documentation/ABI/obsolete/sysfs-bus-iio:12: WARNING: Unexpected indentation.
	Documentation/ABI/obsolete/sysfs-bus-iio:2: WARNING: Unexpected indentation.
	Documentation/ABI/obsolete/sysfs-bus-iio:149: WARNING: Unexpected indentation.

Fixes: caf0fb3b ("iio: Documentation: move incompatible ABI to obsolete")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/602c52c3fb957b9d7d6b72292dc86d295b50c881.1632750608.git.mchehab+huawei@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>