iio: sx9310: Set various settings from DT

These properties need to be set during driver probe. Parse any DT
properties and replace the default register settings with the ones
parsed from DT.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Cc: Daniel Campello <campello@chromium.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: <devicetree@vger.kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20201007011735.1346994-7-swboyd@chromium.org


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