submodule: bump openthread from `fdf3c30` to `efedbe9` (#284)
submodule: bump openthread from `fdf3c30` to `efedbe9` (#284)

Bumps [openthread](https://github.com/openthread/openthread) from `fdf3c30` to `efedbe9`.
- [Commits](https://github.com/openthread/openthread/compare/fdf3c3034f73248d3ddc8e5e0f4519e715ecb287...efedbe9784663fca9cb4a1010b00c2154622254c)

---
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