ASoC: tfa9879: Add device tree bindings

Even though the tfa9879 driver can probe via device tree trough the
I2C core code, it is preferable to have explicit device tree
bindings instead [1], so add this support.

[1] https://www.spinics.net/lists/devicetree/msg195176.html

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Ɓukasz Majewski <lukma@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/tfa9879.c b/sound/soc/codecs/tfa9879.c
index 95e0a7a..f8dd67c 100644
--- a/sound/soc/codecs/tfa9879.c
+++ b/sound/soc/codecs/tfa9879.c
@@ -312,9 +312,15 @@
 };
 MODULE_DEVICE_TABLE(i2c, tfa9879_i2c_id);
 
+static const struct of_device_id tfa9879_of_match[] = {
+	{ .compatible = "nxp,tfa9879", },
+	{ }
+};
+
 static struct i2c_driver tfa9879_i2c_driver = {
 	.driver = {
 		.name = "tfa9879",
+		.of_match_table = tfa9879_of_match,
 	},
 	.probe = tfa9879_i2c_probe,
 	.remove = tfa9879_i2c_remove,