iio: adc: max1027: Fix alignment for DMA safety

____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1.  Switch to the updated
IIO_DMA_MINALIGN definition.

Fixes: fc167f62 ("iio: add support of the max1027")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-24-jic23@kernel.org

drivers/iio/adc/max1027.c

@@ -272,7 +272,7 @@ struct max1027_state {
 	struct mutex			lock;
 	struct completion		complete;
 
-	u8				reg ____cacheline_aligned;
+	u8				reg __aligned(IIO_DMA_MINALIGN);
 };
 
 static int max1027_wait_eoc(struct iio_dev *indio_dev)