iio: light: cm32181: Fix integartion time typo

Fix integartion time typo and while at it improve the comment with
the typo a bit in general.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/cm32181.c

@@ -236,7 +236,7 @@ static int cm32181_reg_init(struct cm32181_chip *cm32181)
  *  @cm32181:	pointer of struct cm32181
  *  @val2:	pointer of int to load the als_it value.
  *
- *  Report the current integartion time by millisecond.
+ *  Report the current integration time in milliseconds.
  *
  *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
  */