iio: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230515205048.19561-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: chemical: sps030: Reformat comment in a more readable way

It's easier to see the (lack of) difference between the lines when they
are visually aligned.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20230129132020.1352368-1-j.neuschaefer@gmx.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: chemical: sps30: Move symbol exports into IIO_SPS30 namespace

Avoid unnecessary pollution of the global symbol namespace by
moving library functions in to a specific namespace and import
that into the drivers that make use of the functions.

For more info: https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Link: https://lore.kernel.org/r/20220220173701.502331-4-jic23@kernel.org
Reviewed-By: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220604155306.422937-4-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: sps30: separate core and interface specific code

Move code responsible for handling i2c communication to a separate file.
Rationale for this change is preparation for adding support for serial
communication.

Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>