configs: Migrate CMD_NAND*

Migrate all remaining instances of CMD_NAND, CMD_NAND_TRIMFFS
CMD_NAND_LOCK_UNLOCK and CMD_NAND_TORTURE from the headers into the
defconfig files.

Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/at91sam9g20ek_2mmc_nandflash_defconfig b/configs/at91sam9g20ek_2mmc_nandflash_defconfig
index 90266fe..5f18f08 100644
--- a/configs/at91sam9g20ek_2mmc_nandflash_defconfig
+++ b/configs/at91sam9g20ek_2mmc_nandflash_defconfig
@@ -15,6 +15,7 @@
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_LOADS is not set
 CONFIG_CMD_MMC=y
+CONFIG_CMD_NAND=y
 CONFIG_CMD_USB=y
 # CONFIG_CMD_FPGA is not set
 # CONFIG_CMD_SOURCE is not set