Update git submodules

* Update external/boringssl from branch 'master'
  to 228bd6249d17f351ea66508b3ec3112ed1cbdf30
  - Revert "external/boringssl: Sync to 81080a729af568f7b5fde92b9170cc17065027c9."
    
    This reverts commit f8d8b73da16aa9f2fdda401a46b4f86a83016712.
    
    Reason for revert: Breaks buildsdk_tools_cross_win
    
    Change-Id: I3bac24f78d165dfa7f89b878cc2277281fd8f1ab
    
1 file changed