Update git submodules

* Update docs/submodules/vfc/nfvo/driver/vnfm/svnfm.git from branch 'master'
  to 91371241b309f0bc39cf195fc46b2c4f2ac49752
  - Add serializer for get vnf pkgs
    
    Change-Id: I8fc30949fc0a8df873c28169f3aa6602c89e0e51
    Issue-ID: VFC-1307
    Signed-off-by: fujinhua <fu.jinhua@zte.com.cn>
    
diff --git a/docs/submodules/vfc/nfvo/driver/vnfm/svnfm.git b/docs/submodules/vfc/nfvo/driver/vnfm/svnfm.git
index 4ea3a43..9137124 160000
--- a/docs/submodules/vfc/nfvo/driver/vnfm/svnfm.git
+++ b/docs/submodules/vfc/nfvo/driver/vnfm/svnfm.git
@@ -1 +1 @@
-Subproject commit 4ea3a430697414352dd709d1108246c9e489d0f4
+Subproject commit 91371241b309f0bc39cf195fc46b2c4f2ac49752