iio: dac: ad5592r: 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: 56ca9db8 ("iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-49-jic23@kernel.org

drivers/iio/dac/ad5592r-base.h

@@ -14,6 +14,8 @@
 #include <linux/mutex.h>
 #include <linux/gpio/driver.h>
 
+#include <linux/iio/iio.h>
+
 struct device;
 struct ad5592r_state;
 
@@ -65,7 +67,7 @@ struct ad5592r_state {
 	u8 gpio_in;
 	u8 gpio_val;
 
-	__be16 spi_msg ____cacheline_aligned;
+	__be16 spi_msg __aligned(IIO_DMA_MINALIGN);
 	__be16 spi_msg_nop;
 };