Convert CONFIG_NAND_LPC32XX_SLC to Kconfig

This converts the following to Kconfig:
   CONFIG_NAND_LPC32XX_SLC

Signed-off-by: Adam Ford <aford173@gmail.com>

configs/devkit3250_defconfig

@@ -34,6 +34,7 @@ CONFIG_DM_GPIO=y
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_NAND=y
+CONFIG_NAND_LPC32XX_SLC=y
 CONFIG_SPL_NAND_SIMPLE=y
 CONFIG_PHYLIB=y
 CONFIG_PHY_ADDR_ENABLE=y

drivers/mtd/nand/Kconfig

@@ -31,6 +31,11 @@ config NAND_DENALI_SPARE_AREA_SKIP_BYTES
 	  of OOB area before last ECC sector data starts.  This is potentially
 	  used to preserve the bad block marker in the OOB area.
 
+config NAND_LPC32XX_SLC
+	bool "Support LPC32XX_SLC controller"
+	help
+	  Enable the LPC32XX SLC NAND controller.
+
 config NAND_OMAP_GPMC
 	bool "Support OMAP GPMC NAND controller"
 	depends on ARCH_OMAP2PLUS

include/configs/devkit3250.h

@@ -84,7 +84,6 @@
 /*
  * NAND controller
  */
-#define CONFIG_NAND_LPC32XX_SLC
 #define CONFIG_SYS_NAND_BASE		SLC_NAND_BASE
 #define CONFIG_SYS_MAX_NAND_DEVICE	1
 #define CONFIG_SYS_NAND_BASE_LIST	{ CONFIG_SYS_NAND_BASE }

scripts/config_whitelist.txt

@@ -1380,7 +1380,6 @@ CONFIG_NAND_FSMC
 CONFIG_NAND_KIRKWOOD
 CONFIG_NAND_KMETER1
 CONFIG_NAND_LPC32XX_MLC
-CONFIG_NAND_LPC32XX_SLC
 CONFIG_NAND_MODE_REG
 CONFIG_NAND_MXC_V1_1
 CONFIG_NAND_OMAP_ECCSCHEME