ASoC: omap-mcbsp: Check mcbsp->id instead of cpu_dai->id when adding ST controls

In ddevice tree booted kernel all device have unique name and their device
id is set to 0.
Use the mcbsp->id for checking to decide which control set we should add
for McBSP sidetone handling.

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 2e1750e..20d30c9 100644
--- a/sound/soc/omap/omap-mcbsp.c
+++ b/sound/soc/omap/omap-mcbsp.c
@@ -722,7 +722,7 @@
 	if (!mcbsp->st_data)
 		return -ENODEV;
 
-	switch (cpu_dai->id) {
+	switch (mcbsp->id) {
 	case 2: /* McBSP 2 */
 		return snd_soc_add_dai_controls(cpu_dai,
 					omap_mcbsp2_st_controls,