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/gurnard_defconfig b/configs/gurnard_defconfig
index d90dbe6..c32c4a8 100644
--- a/configs/gurnard_defconfig
+++ b/configs/gurnard_defconfig
@@ -14,6 +14,7 @@
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_LOADS is not set
 # CONFIG_CMD_FLASH is not set
+CONFIG_CMD_NAND=y
 CONFIG_CMD_PART=y
 # CONFIG_CMD_FPGA is not set
 CONFIG_CMD_GPIO=y