fmap.py: use argparse for parsing the command line

This makes the code easier to manage and provides automatic support
for things like -h/--help.

BUG=chromium:982465
TEST=`./fmap.py bin/example.bin` works

Change-Id: I7a45d414cb2ed2d23bf65978b9dd06e05fc99cd7
Reviewed-on: https://chromium-review.googlesource.com/1693883
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@google.com>
1 file changed