Convert CONFIG_MTD_CONCAT to Kconfig

This converts the following to Kconfig:
  CONFIG_MTD_CONCAT

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/configs/etamin_defconfig b/configs/etamin_defconfig
index ba7a066..34b9fff 100644
--- a/configs/etamin_defconfig
+++ b/configs/etamin_defconfig
@@ -87,6 +87,7 @@
 # CONFIG_SPL_DM_MMC is not set
 CONFIG_MMC_OMAP_HS=y
 CONFIG_MTD=y
+CONFIG_MTD_CONCAT=y
 CONFIG_MTD_RAW_NAND=y
 CONFIG_NAND_OMAP_ECCSCHEME_BCH16_CODE_HW=y
 CONFIG_SYS_NAND_BLOCK_SIZE=0x80000
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 588ebe9..4088267 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -22,6 +22,14 @@
 	help
 	  Enable support for parallel NOR flash.
 
+config MTD_CONCAT
+	bool "Enable MTD device concatenation"
+	depends on MTD
+	help
+	  Enable support for concatenating multiple physical MTD devices
+	  into a single logical device. The larger logical device can then
+	  be partitioned.
+
 config SYS_MTDPARTS_RUNTIME
 	bool "Allow MTDPARTS to be configured at runtime"
 	depends on MTD
diff --git a/include/configs/etamin.h b/include/configs/etamin.h
index dc83ab7..9cf9392 100644
--- a/include/configs/etamin.h
+++ b/include/configs/etamin.h
@@ -151,7 +151,6 @@
 #define ETAMIN_NAND_GPMC_CONFIG4	0x16051807
 #define ETAMIN_NAND_GPMC_CONFIG5	0x00151e1e
 #define ETAMIN_NAND_GPMC_CONFIG6	0x16000f80
-#define CONFIG_MTD_CONCAT
 
 /* Default env settings */
 #define CONFIG_EXTRA_ENV_SETTINGS \
diff --git a/include/configs/octeontx_common.h b/include/configs/octeontx_common.h
index bcf8b41..81dbff2 100644
--- a/include/configs/octeontx_common.h
+++ b/include/configs/octeontx_common.h
@@ -64,7 +64,6 @@
 /** EMMC specific defines */
 
 #if defined(CONFIG_NAND_OCTEONTX)
-/*#define CONFIG_MTD_CONCAT */
 #define CONFIG_SYS_MAX_NAND_DEVICE 8
 #endif
 
diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt
index 5b882b2..cecdda6 100644
--- a/scripts/config_whitelist.txt
+++ b/scripts/config_whitelist.txt
@@ -389,7 +389,6 @@
 CONFIG_MONITOR_IS_IN_RAM
 CONFIG_MPC85XX_FEC
 CONFIG_MPC85XX_FEC_NAME
-CONFIG_MTD_CONCAT
 CONFIG_MTD_NAND_VERIFY_WRITE
 CONFIG_MTD_PARTITION
 CONFIG_MVGBE_PORTS