fastboot: support make_f2fs and sload_f2fs for win32

This patch enalbes to use windows tools for f2fs.

Change-Id: Id9109d3d1d8db85f433a20c6a9b18a88daa540d0
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
(cherry picked from commit aa64620e)