iio: fix doc for iio_gts_find_sel_by_int_time

The kerneldoc for iio_gts_find_sel_by_int_time() has an error.
Documentation states that function is searching a selector for a HW-gain
while it is searching a selector for an integration time.

Fix the documentation by saying the function is looking for a selector
for an integration time.

Fixes: 38416c28 ("iio: light: Add gain-time-scale helpers")
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/ZEIjI4YUzqPZk/9X@fedoraSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

include/linux/iio/iio-gts-helper.h

@@ -135,7 +135,7 @@ static inline int iio_gts_find_int_time_by_sel(struct iio_gts *gts, int sel)
 /**
  * iio_gts_find_sel_by_int_time - find selector matching integration time
  * @gts:	Gain time scale descriptor
- * @gain:	HW-gain for which matching selector is searched for
+ * @time:	Integration time for which matching selector is searched for
  *
  * Return:	a selector matching given integration time or -EINVAL if
  *		selector was not found.