Update git submodules

* Update docs/submodules/integration.git from branch 'master'
  to ef648d52e53e36b735e97dd40788c9e27d90100f
  - [INT-1450] : Documentation of PNF Software Upgrade
    
    This contains documentation for PNF Software Upgrade
    using Netconf/Yang interface with EM
    
    Issue-ID: INT-1450
    Signed-off-by: Darragh Egan <darragh.egan@est.tech>
    Change-Id: I8a225b5a4b08de2004ff327148fadfff8976c5de
    
1 file changed