iio: adc: dln2: Use aligned_s64 for timestamp

Here the lack of marking allows the overall structure to not be
sufficiently aligned resulting in misplacement of the timestamp
in iio_push_to_buffers_with_timestamp(). Use aligned_s64 to
force the alignment on all architectures.

Fixes: 7c0299e ("iio: adc: Add support for DLN2 ADC")
Reported-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250413103443.2420727-4-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/dln2-adc.c

@@ -466,7 +466,7 @@ static irqreturn_t dln2_adc_trigger_h(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct {
 		__le16 values[DLN2_ADC_MAX_CHANNELS];
-		int64_t timestamp_space;
+		aligned_s64 timestamp_space;
 	} data;
 	struct dln2_adc_get_all_vals dev_data;
 	struct dln2_adc *dln2 = iio_priv(indio_dev);