submodule: bump openthread from `f4e1526` to `56ce8e2` (#169)
submodule: bump openthread from `f4e1526` to `56ce8e2` (#169)

Bumps [openthread](https://github.com/openthread/openthread) from `f4e1526` to `56ce8e2`.
- [Commits](https://github.com/openthread/openthread/compare/f4e1526a49e8cfc373d2458b6174b9ee9e608149...56ce8e259308399200def7c70e3a6fea461451f0)

---
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