iio: adc: ad7173: fix using shared static info struct

Fix a possible race condition during driver probe in the ad7173 driver
due to using a shared static info struct. If more that one instance of
the driver is probed at the same time, some of the info could be
overwritten by the other instance, leading to incorrect operation.

To fix this, make the static info struct const so that it is read-only
and make a copy of the info struct for each instance of the driver that
can be modified.

Reported-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Fixes: 76a1e6a4 ("iio: adc: ad7173: add AD7173 driver")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Tested-by: Guillaume Ranquet <granquet@baylibre.com>
Link: https://patch.msgid.link/20241127-iio-adc-ad7313-fix-non-const-info-struct-v2-1-b6d7022b7466@baylibre.com


Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>