submodule: bump openthread from `0b8e974` to `5516024` (#332)
submodule: bump openthread from `0b8e974` to `5516024` (#332)

Bumps [openthread](https://github.com/openthread/openthread) from `0b8e974` to `5516024`.
- [Commits](https://github.com/openthread/openthread/compare/0b8e9745e5c54632730a65faa0cab146cc3f88b7...551602490555033a010ed4b4649821df4b2b882d)

---
updated-dependencies:
- dependency-name: openthread
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-cc2538,openthread/ot-cc2538