staging: iio: ad5933: add device tree support

Add a of_device_id struct variable and subsequent call to
MODULE_DEVICE_TABLE macro to complete device tree support.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/impedance-analyzer/ad5933.c

@@ -786,9 +786,18 @@ static const struct i2c_device_id ad5933_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, ad5933_id);
 
+static const struct of_device_id ad5933_of_match[] = {
+	{ .compatible = "adi,ad5933" },
+	{ .compatible = "adi,ad5934" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, ad5933_of_match);
+
 static struct i2c_driver ad5933_driver = {
 	.driver = {
 		.name = "ad5933",
+		.of_match_table = ad5933_of_match,
 	},
 	.probe = ad5933_probe,
 	.remove = ad5933_remove,