submodule: bump openthread from `0a6a0b6` to `4c117b9` (#86)
submodule: bump openthread from `0a6a0b6` to `4c117b9` (#86)

Bumps [openthread](https://github.com/openthread/openthread) from `0a6a0b6` to `4c117b9`.
- [Commits](https://github.com/openthread/openthread/compare/0a6a0b6604240e2476c2f1afbba82b2fa2a33575...4c117b92deff14f9df14898349d9f38f948450fa)

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

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

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-efr32,openthread/ot-efr32,openthread/ot-efr32