iio:dac:ad5755 replaces IIO_ST macro with explicit entries to struct scan_type

IIO_ST is going away as it is a pain to maintain.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>

drivers/iio/dac/ad5755.c

@@ -392,7 +392,12 @@ static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
 		BIT(IIO_CHAN_INFO_OFFSET) |			\
 		BIT(IIO_CHAN_INFO_CALIBSCALE) |			\
 		BIT(IIO_CHAN_INFO_CALIBBIAS),			\
-	.scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)),	\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = (_bits),				\
+		.storagebits = 16,				\
+		.shift = 16 - (_bits),				\
+	},							\
 	.ext_info = ad5755_ext_info,				\
 }