moveconfig: Convert to ArgumentParser

moveconfig: Convert to ArgumentParser

This is a newer library and is now preferred for Python scripts. Update
the code to use it instead of optparse

Use 'args' instead of 'options' throughout, since this is the term used
in that module. Also it helps to avoid confusion with CONFIG options, a
term that is used in this file.

Signed-off-by: Simon Glass <sjg@chromium.org>