ASoC: zx: Add zx296702 SPDIF support

Add driver for zx296702 SPDIF controller

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 3ba52da..e2828e1 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -57,6 +57,7 @@
 source "sound/soc/txx9/Kconfig"
 source "sound/soc/ux500/Kconfig"
 source "sound/soc/xtensa/Kconfig"
+source "sound/soc/zte/Kconfig"
 
 # Supported codecs
 source "sound/soc/codecs/Kconfig"