Update git submodules

* Update external/dtc from branch 'master'
  to 2f467160498f43f671339befc86a3470a4286051
  - Add default code reviewers into OWNERS
    
    Bug: 33166666
    Test: gerrit uploader
    Change-Id: I764a14f53094c561a5a9672a559fec70a84c735f
    
1 file changed