ARM: EXYNOS4: Fix build warning on regarding SATA_AHCI_PLATFORM

This patch fixes following build warnings.

warning: (MACH_ARMLEX4210) selects SATA_AHCI_PLATFORM
          which has unmet direct dependencies (ATA)

And adds EXYNOX4_DEV_AHCI for building machines which are
not suppoort for AHCI feature on board.
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos4/Kconfig

@@ -20,6 +20,11 @@ config EXYNOS4_MCT
 	help
 	  Use MCT (Multi Core Timer) as kernel timers
 
+config EXYNOS4_DEV_AHCI
+	bool
+	help
+	  Compile in platform device definitions for AHCI
+
 config EXYNOS4_DEV_PD
 	bool
 	help
@@ -134,9 +139,9 @@ config MACH_ARMLEX4210
 	select S3C_DEV_HSMMC
 	select S3C_DEV_HSMMC2
 	select S3C_DEV_HSMMC3
+	select EXYNOS4_DEV_AHCI
 	select EXYNOS4_DEV_SYSMMU
 	select EXYNOS4_SETUP_SDHCI
-	select SATA_AHCI_PLATFORM
 	help
 	  Machine support for Samsung ARMLEX4210 based on EXYNOS4210
 

arch/arm/mach-exynos4/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_MACH_NURI)			+= mach-nuri.o
 # device support
 
 obj-y					+= dev-audio.o
+obj-$(CONFIG_EXYNOS4_DEV_AHCI)		+= dev-ahci.o
 obj-$(CONFIG_EXYNOS4_DEV_PD)		+= dev-pd.o
 obj-$(CONFIG_EXYNOS4_DEV_SYSMMU)	+= dev-sysmmu.o
 
@@ -53,4 +54,3 @@ obj-$(CONFIG_EXYNOS4_SETUP_I2C7)	+= setup-i2c7.o
 obj-$(CONFIG_EXYNOS4_SETUP_KEYPAD)	+= setup-keypad.o
 obj-$(CONFIG_EXYNOS4_SETUP_SDHCI)	+= setup-sdhci.o
 obj-$(CONFIG_EXYNOS4_SETUP_SDHCI_GPIO)	+= setup-sdhci-gpio.o
-obj-$(CONFIG_SATA_AHCI_PLATFORM)	+= dev-ahci.o