Rather than using CMD_JFFS2 for both the filesystem and its command, we
should have a separate option for each. This allows us to enable JFFS2
support without the command, if desired, which reduces U-Boot's size
slightly.
config FS_JFFS2
bool "Enable JFFS2 filesystem support"
help
This provides support for reading images from JFFS2 (Journalling
Flash File System version 2). JFFS2 is a log-structured file system
for use with flash memory devices. It supports raw NAND devices,
hard links and compression.