iio: dac: max5821: Fix module autoload for OF platform driver

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/dac/max5821.c

@@ -387,6 +387,7 @@ static const struct of_device_id max5821_of_match[] = {
 	{ .compatible = "maxim,max5821" },
 	{ }
 };
+MODULE_DEVICE_TABLE(of, max5821_of_match);
 
 static struct i2c_driver max5821_driver = {
 	.driver = {