[otbn] Re-enable smoke test in CI (again)
[otbn] Re-enable smoke test in CI (again)

Re-re-enable it: we should now have a working out-of-tree ISS plus
support for address errors.

Signed-off-by: Rupert Swarbrick <290093e2ad2515ed2f14d749293c8cf8e02ca274@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan