ARM: da850-evm: Enable filesystem commands when booting from NOR

The configuration with NOR is mutually exclusive with MMC, and as
such, the filesystem commands were disabled.  With the USB host
enabled, this patch enables the file system command which can
be executed on storage devices attached to the USB.
Signed-off-by: NAdam Ford <aford173@gmail.com>

configs/da850evm_direct_nor_defconfig

@@ -29,10 +29,6 @@ CONFIG_CMD_MTD=y
 # CONFIG_CMD_SPI is not set
 # CONFIG_CMD_SETEXPR is not set
 # CONFIG_CMD_TIME is not set
-# CONFIG_CMD_EXT2 is not set
-# CONFIG_CMD_EXT4 is not set
-# CONFIG_CMD_FAT is not set
-# CONFIG_CMD_FS_GENERIC is not set
 CONFIG_CMD_MTDPARTS=y
 CONFIG_MTDIDS_DEFAULT="nor0=physmap-flash.2"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=physmap-flash.2:1m(u-boot),128k(u-boot-env),-(spare)"