[Submodule update] sonic-util

 [201911][thermal control] Backport changes from master branch (sonic-net#929)
     [201911][config] Support abbreviation (sonic-net#933)
       Add 'hw-management-generate-dump.sh' to 'show techsupport'
       command (sonic-net#934)
       [fwutil]: Update fwutil to v2.0.0.0. (sonic-net#942)
       Fixes bug for PFCWD feature parameters (sonic-net#838)
     Fixed fast-reboot for BFN platform (sonic-net#871)
     [config] Add 'interface transceiver' subgroup with 'lpmode' and
     'reset' subcommands (sonic-net#904)
      [warm-reboot]: added pre-check for ISSU file (sonic-net#915)
       [config] Don't attempt to restart disabled services (sonic-net#944)