iio: fix write_event_config signature

iio: fix write_event_config signature

write_event_config callback use an int for state, but it is actually a
boolean. iio_ev_state_store is actually using kstrtobool to check user
input, then gives the converted boolean value to write_event_config.

Fix signature and update all iio drivers to use the new signature.

This patch has been partially written using coccinelle with the
following script:

$ cat iio-bool.cocci
// Options: --all-includes

virtual patch

@c1@
identifier iioinfo;
identifier wecfunc;
@@
 static const struct iio_info iioinfo = {
        ...,
        .write_event_config =
(
 wecfunc
|
 &wecfunc
),
        ...,
 };

@@
identifier c1.wecfunc;
identifier indio_dev, chan, type, dir, state;
@@
 int wecfunc(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir,
-int
+bool
 state) {
  ...
 }

make coccicheck MODE=patch COCCI=iio-bool.cocci M=drivers/iio

Unfortunately, this script didn't match all files:
* all write_event_config callbacks using iio_device_claim_direct_scoped
  were not detected and not patched.
* all files that do not assign and declare the write_event_config
  callback in the same file.

iio.h was also manually updated.

The patch was build tested using allmodconfig config.

cc: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Link: https://patch.msgid.link/20241031-iio-fix-write-event-config-signature-v2-7-2bcacbb517a2@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>