Update git submodules

* Update docs/submodules/sdc/sdc-docker-base.git from branch 'master'
  to a6b20ce3648af25f1c4d4aad61503da6f861eda1
  - Bump Base dockers version to 1.6.1
    
    Change-Id: If700e171c7862b29d7c5c86663cd06c3c88cb890
    Issue-ID: SDC-2595
    Signed-off-by: Ofir Sonsino <os0695@intl.att.com>
    
1 file changed