Update git submodules

* Update docs/submodules/vnfrqts/requirements.git from branch 'master'
  to 171c450a84e41e352205e0aabc6ecb6e1d9013a6
  - Merge "Adding newest 3GPP XML bulkPM file schema to BulkPM rqts"
  - Adding newest 3GPP XML bulkPM file schema to BulkPM rqts

    In Rel-16, 3GPP has published an updated BulkPM schema in TS 28.532 standard.
    Support for previous TS 28.550 schema was added in Frankfurt already, it will be updated now in Guilin to 28.532.

    Change-Id: Idc9b1229b7ca3de09f8c0fe4869465abfb4e4814
    Signed-off-by: deen1985 <damian.nowak@nokia.com>
    Issue-ID: VNFRQTS-894
    Signed-off-by: deen1985 <damian.nowak@nokia.com>