Convert CONFIG_NAND to Kconfig

This converts the following to Kconfig:
   CONFIG_NAND

Signed-off-by: Adam Ford <aford173@gmail.com>
[trini: Sync up a few more, add imply's]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 43096d0..61d8d31 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -706,6 +706,7 @@
 	select CPU_V7
 	select SYS_FSL_ERRATUM_ESDHC111
 	imply CMD_MTDPARTS
+	imply NAND
 
 config ARCH_ZYNQ
 	bool "Xilinx Zynq Platform"