lib/bb/utils.py: Fix explode_dep_versions2() determinism issue

lib/bb/utils.py: Fix explode_dep_versions2() determinism issue

When we pass data into explode_dep_versions2(), we need to result to be
able to be processed in a deterministic way so that we end up with
consistent hash values. This means we need an ordered structure rather
than an unordered one.

To do this, return an OrderedDict() rather than a dict().

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>