rtc: rtc-ds1672: Add OF device ID table

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-ds1672.c

@@ -196,10 +196,17 @@ static struct i2c_device_id ds1672_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ds1672_id);
 
+static const struct of_device_id ds1672_of_match[] = {
+	{ .compatible = "dallas,ds1672" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds1672_of_match);
+
 static struct i2c_driver ds1672_driver = {
 	.driver = {
 		   .name = "rtc-ds1672",
-		   },
+		   .of_match_table = of_match_ptr(ds1672_of_match),
+	},
 	.probe = &ds1672_probe,
 	.id_table = ds1672_id,
 };