iio: adc: twl6030-gpadc: 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/adc/twl6030-gpadc.c

@@ -875,6 +875,7 @@ static const struct of_device_id of_twl6030_match_tbl[] = {
 	},
 	{ /* end */ }
 };
+MODULE_DEVICE_TABLE(of, of_twl6030_match_tbl);
 
 static int twl6030_gpadc_probe(struct platform_device *pdev)
 {