This is a pretty fundamental module, and even minimal ports like unix and
zephyr minimal have it enabled. So, enabled it by default at the lowest
feature level.
Most things in the `sys` module are configurable, and off by default, so it
shouldn't add too much to ports that don't already have it enabled (which
is just the minimal port).
Also note that `sys` is still disabled on the bare-arm port, to keep that
ultra minimal. It means we now have bare-arm without `sys` and the minimal
port with `sys`. That will allow different code size comparisons if/when
new `sys` features are added.
Signed-off-by: Damien George <damien@micropython.org>
