iio: adc: ti-adc128s052: 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: 913b8646 ("iio: adc: Add TI ADC128S052")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-33-jic23@kernel.org

drivers/iio/adc/ti-adc128s052.c

@@ -29,7 +29,7 @@ struct adc128 {
 	struct regulator *reg;
 	struct mutex lock;
 
-	u8 buffer[2] ____cacheline_aligned;
+	u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
 };
 
 static int adc128_adc_conversion(struct adc128 *adc, u8 channel)