Update git submodules

Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to f81920304c7b62637d32473e672a1e51275ce54b
  - Merge "PNF WF post instantiation configuration"
  - PNF WF post instantiation configuration

    Add PNF ipv4/v6 address for config Deploy
    Add Integration test for CreateVcpeResCustService_simplified.bpmn
    Modify the PnfEventReadyDmaapClient to avoid one more running thread
    Refactor the so-bpmn-infrastructure-flows test resources
    Modify the CreateVcpeResCustService_simplified.bpmn
    Add ConfigurePnfResource.bpmn
    Add Delegates

    Issue-ID: SO-1506
    Change-Id: Iffb69d1441ef0b485ee8cd3fb5da5f1a35279a95
    Signed-off-by: eeginux <henry.xie@est.tech>