Blackfin arch: Disable NAND option by default

Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

arch/blackfin/configs/BF537-STAMP_defconfig

@@ -568,15 +568,7 @@ CONFIG_MTD_PHYSMAP_BANKWIDTH=2
 # CONFIG_MTD_DOC2000 is not set
 # CONFIG_MTD_DOC2001 is not set
 # CONFIG_MTD_DOC2001PLUS is not set
-CONFIG_MTD_NAND=m
-# CONFIG_MTD_NAND_VERIFY_WRITE is not set
-# CONFIG_MTD_NAND_ECC_SMC is not set
-# CONFIG_MTD_NAND_MUSEUM_IDS is not set
-# CONFIG_MTD_NAND_BFIN is not set
-CONFIG_MTD_NAND_IDS=m
-# CONFIG_MTD_NAND_DISKONCHIP is not set
-# CONFIG_MTD_NAND_NANDSIM is not set
-CONFIG_MTD_NAND_PLATFORM=m
+# CONFIG_MTD_NAND is not set
 # CONFIG_MTD_ONENAND is not set
 
 #