mx6cuboxi: Move CONFIG_CMD_SATA to Kconfig

Move CONFIG_CMD_SATA option to Kconfig to fix the following build
error:

In file included from include/configs/mx6cuboxi.h:137:0,
                 from include/config.h:7,
                 from include/common.h:21,
                 from common/env_common.c:11:
include/config_distro_bootcmd.h:161:2: error: expected '}' before 'BOOT_TARGET_DEVICES_references_SATA_without_CONFIG_SATA'
  BOOT_TARGET_DEVICES_references_SATA_without_CONFIG_SATA
Reported-by: NStefano Babic <sbabic@denx.de>
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>

configs/mx6cuboxi_defconfig

@@ -23,6 +23,7 @@ CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_GPIO=y
+CONFIG_CMD_SATA=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_EXT4_WRITE=y
 # CONFIG_SPL_PARTITION_UUIDS is not set

include/configs/mx6cuboxi.h

@@ -22,7 +22,6 @@
 #define CONFIG_SYS_FSL_ESDHC_ADDR	USDHC2_BASE_ADDR
 
 /* SATA Configuration */
-#define CONFIG_CMD_SATA
 #ifdef CONFIG_CMD_SATA
 #define CONFIG_DWC_AHSATA
 #define CONFIG_SYS_SATA_MAX_DEVICE      1