ASoC: ads117x: Add device tree compatible string

This patch adds the necessary device tree compatible string to allow DT
probing.

Signed-off-by: Florian Vaussard <florian.vaussard@heig-vd.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/ads117x.c b/sound/soc/codecs/ads117x.c
index 1222282..c5be1bd 100644
--- a/sound/soc/codecs/ads117x.c
+++ b/sound/soc/codecs/ads117x.c
@@ -20,6 +20,8 @@
 #include <sound/initval.h>
 #include <sound/soc.h>
 
+#include <linux/of.h>
+
 #define ADS117X_RATES (SNDRV_PCM_RATE_8000_48000)
 #define ADS117X_FORMATS (SNDRV_PCM_FMTBIT_S16_LE)
 
@@ -75,9 +77,19 @@
 	return 0;
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id ads117x_dt_ids[] = {
+	{ .compatible = "ti,ads1174" },
+	{ .compatible = "ti,ads1178" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ads117x_dt_ids);
+#endif
+
 static struct platform_driver ads117x_codec_driver = {
 	.driver = {
 			.name = "ads117x-codec",
+			.of_match_table = of_match_ptr(ads117x_dt_ids),
 	},
 
 	.probe = ads117x_probe,