iio: adc: ti-ads8688: Fix alignment of buffer in iio_push_to_buffers_with_timestamp()

Add __aligned(8) to ensure the buffer passed to
iio_push_to_buffers_with_timestamp() is suitable for the naturally
aligned timestamp that will be inserted.

Fixes: f214ff52 ("iio: ti-ads8688: Update buffer allocation for timestamps")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210613152301.571002-5-jic23@kernel.org

drivers/iio/adc/ti-ads8688.c

@@ -383,7 +383,8 @@ static irqreturn_t ads8688_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
-	u16 buffer[ADS8688_MAX_CHANNELS + sizeof(s64)/sizeof(u16)];
+	/* Ensure naturally aligned timestamp */
+	u16 buffer[ADS8688_MAX_CHANNELS + sizeof(s64)/sizeof(u16)] __aligned(8);
 	int i, j = 0;
 
 	for (i = 0; i < indio_dev->masklength; i++) {