ASoC: cs42l51: add Device Tree binding to cs42l51

This commit adds a trivial Device Tree binding to the I2C-based
cs42l51 sound codec, so that it can be used from Device Tree based
platforms.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/i2c/trivial-devices.txt

@@ -18,6 +18,7 @@ atmel,24c02		i2c serial eeprom  (24cxx)
 atmel,at97sc3204t	i2c trusted platform module (TPM)
 capella,cm32181		CM32181: Ambient Light Sensor
 catalyst,24c32		i2c serial eeprom
+cirrus,cs42l51		Cirrus Logic CS42L51 audio codec
 dallas,ds1307		64 x 8, Serial, I2C Real-Time Clock
 dallas,ds1338		I2C RTC with 56-Byte NV RAM
 dallas,ds1339		I2C Serial Real-Time Clock

sound/soc/codecs/cs42l51.c

@@ -600,10 +600,17 @@ static const struct i2c_device_id cs42l51_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, cs42l51_id);
 
+static const struct of_device_id cs42l51_of_match[] = {
+	{ .compatible = "cirrus,cs42l51", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, cs42l51_of_match);
+
 static struct i2c_driver cs42l51_i2c_driver = {
 	.driver = {
 		.name = "cs42l51-codec",
 		.owner = THIS_MODULE,
+		.of_match_table = cs42l51_of_match,
 	},
 	.id_table = cs42l51_id,
 	.probe = cs42l51_i2c_probe,