Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Updated project description to clarify VSPERF independence from Open Stack

    Change-Id: Iab653c7ad1cf6cbdb9c15056337a2768a489a87a
    Signed-off-by: Trevor Cooper <trevor.cooper@intel.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index 5d08ffd..bf1b0f8 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit 5d08ffdf317d31361a528bf1b6d33cd4d0007600
+Subproject commit bf1b0f81b1c79729433faa2bbf35a3cd7478066b