sandbox: exynos: Move CONFIG_I2S to Kconfig

Move this over to Kconfig and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>

configs/arndale_defconfig

@@ -5,3 +5,4 @@ CONFIG_TARGET_ARNDALE=y
 CONFIG_DEFAULT_DEVICE_TREE="exynos5250-arndale"
 CONFIG_SOUND=y
 CONFIG_CMD_SOUND=y
+CONFIG_I2S=y

configs/smdk5250_defconfig

@@ -5,3 +5,4 @@ CONFIG_TARGET_SMDK5250=y
 CONFIG_DEFAULT_DEVICE_TREE="exynos5250-smdk5250"
 CONFIG_SOUND=y
 CONFIG_CMD_SOUND=y
+CONFIG_I2S=y

configs/snow_defconfig

@@ -9,3 +9,4 @@ CONFIG_CROS_EC_KEYB=y
 CONFIG_CMD_CROS_EC=y
 CONFIG_SOUND=y
 CONFIG_CMD_SOUND=y
+CONFIG_I2S=y

drivers/sound/Kconfig

@@ -9,3 +9,12 @@ config SOUND
 	  Note: At present the sound setup is somewhat tangled up in that the
 	  audio codecs are called from the sound-i2s code. This could be
 	  converted to driver model.
+
+config I2S
+	bool "Enable I2S support"
+	depends on SOUND
+	help
+	  I2S is a serial bus often used to transmit audio data from the
+	  SoC to the audio codec. This option enables sound support using
+	  I2S. It calls either of the two supported codecs (no use is made
+	  of driver model at present).

include/configs/exynos5250-common.h

@@ -31,7 +31,6 @@
 /* Sound */
 #ifdef CONFIG_CMD_SOUND
 #define CONFIG_I2S_SAMSUNG
-#define CONFIG_I2S
 #define CONFIG_SOUND_MAX98095
 #define CONFIG_SOUND_WM8994
 #endif