docs: ABI: testing: make the files compatible with ReST output

Some files over there won't parse well by Sphinx.

Fix them.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: hmc5843: Add ABI documentation file for hmc5843

Add ABI file documenting hmc5843 non-standard attributes
meas_conf and meas_conf_available for bias current
configuration.

Signed-off-by: Cristina Moraru <cristina.moraru09@gmail.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>