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>
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index bdc2721..dad5711 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -31,6 +31,11 @@
 	  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