[ELDK] [RFSB] mkfs.jffs2 build options

[Ron Madrid]

Whenever I've built my jffs2 image (manually) I have
used a few options that are currently not supported by
the RFSB.  I am guessing because no one has bothered to
add these capabilities up to this point.  The options
that I have been using are -n, --pad, and -s.  The fact
that these aren't included makes me think that perhaps
I'm using these options unnecessarily.

If it is simply the case that no one has needed them
until now I'd be happy to supply a patch to add these
options.  Any feedback would be great.

Ron