Update git submodules

Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 78071bdcd6307acced45ca490d33897347338b99
  - Merge changes I910db5fe,I269f4e20,I2ad55d49,I1cb6eee0,Ifa375512, ...

    * changes:
      add vid based apis details
      add uui based apis details
      add vid based instantiation flows
      add e2e flow details
      add pnf instantiate flows
      add the NBI section to the instantiate flows

  - add vid based apis details

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: I910db5fe7e2006ec3808ce738fd11fb9b061e47a

  - add uui based apis details

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: I269f4e20e0c30168a97ef3db056a69fefd564eac

  - add vid based instantiation flows

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: I2ad55d49bd1be2a684354f958dcbe93cf0dbaf17

  - add e2e flow details

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: I1cb6eee09292ed206a4315e1e9245d35256fd357

  - add pnf instantiate flows

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: Ifa375512d97aa5f9c56156a20eae5e220ef0039c

  - add the NBI section to the instantiate flows

    Issue-ID: SO-608

    Signed-off-by: seshukm <seshu.kumar.m@huawei.com>
    Change-Id: I5567a89fa36aa85397a3472147e7848f44561a48