Update git submodules

* Update external/lk from branch 'master'
  to 8a358464cdea5c6ecf986d6ea630e8dbcfcef279
  - [arch][arm] Dump back trace on error
    
    Needed for local debugging and wild bug reports.
    Also, added lib/backtrace and lib/trusty as dependencies since their
    functions are called unconditionally.
    
    Bug: 149918767
    Change-Id: Iabbb5beb41c2542b502858da51ba21b80913d06d
    
1 file changed