ASoC: omap-mcbsp: Only print warning if the st_data is missing for the port

When asked to add the ST controls warn only if the st_data is missing.
In this way we do not block the otherwise functional card to probe.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index 20d30c9..c1f466e 100644
--- a/sound/soc/omap/omap-mcbsp.c
+++ b/sound/soc/omap/omap-mcbsp.c
@@ -719,8 +719,10 @@
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	struct omap_mcbsp *mcbsp = snd_soc_dai_get_drvdata(cpu_dai);
 
-	if (!mcbsp->st_data)
-		return -ENODEV;
+	if (!mcbsp->st_data) {
+		dev_warn(mcbsp->dev, "No sidetone data for port\n");
+		return 0;
+	}
 
 	switch (mcbsp->id) {
 	case 2: /* McBSP 2 */