iio:ad7797: Use correct attribute_group

It should use ad7797_attribute_group in ad7797_info,
according to commit ("iio:ad7793: Add support for the ad7796 and ad7797").

Scale is fixed for the ad7796 and not programmable, hence
should not have the scale_available attribute.

Fixes: fd1a8b91 ("iio:ad7793: Add support for the ad7796 and ad7797")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7793.c

@@ -542,7 +542,7 @@ static const struct iio_info ad7797_info = {
 	.read_raw = &ad7793_read_raw,
 	.write_raw = &ad7793_write_raw,
 	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
-	.attrs = &ad7793_attribute_group,
+	.attrs = &ad7797_attribute_group,
 	.validate_trigger = ad_sd_validate_trigger,
 };