ASoC: Add ability to build sti drivers

Define the platform and codec drivers, and how to build them.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 2ae9619..467ee1a 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -54,6 +54,7 @@
 source "sound/soc/sh/Kconfig"
 source "sound/soc/sirf/Kconfig"
 source "sound/soc/spear/Kconfig"
+source "sound/soc/sti/Kconfig"
 source "sound/soc/tegra/Kconfig"
 source "sound/soc/txx9/Kconfig"
 source "sound/soc/ux500/Kconfig"