iio: core: Fix mapping of iio channels to entry numbers

When adding maps to the list, they were added using list_add, which adds
them in LIFO order. When parsing using iio_channel_get_all(), these
elements are hence returned in reverse order. As a result, the iio_hwmon
mapping maps the first entry to the last channel and so on.
Signed-off-by: Gaurav Gupta <gauragup@cisco.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/inkern.c

@@ -44,7 +44,7 @@ int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
 		}
 		mapi->map = &maps[i];
 		mapi->indio_dev = indio_dev;
-		list_add(&mapi->l, &iio_map_list);
+		list_add_tail(&mapi->l, &iio_map_list);
 		i++;
 	}
 error_ret: