Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "Removed drafts of test specificaiton now published as RFC8204. Also removed IETF license notice and added a file with link to RFC8204"
  - Removed drafts of test specificaiton now published as RFC8204. Also removed IETF license notice and added
    a file with link to RFC8204

    Change-Id: I44b4cb75afeff74a58f402a7cb8816ddfbe52b87
    Signed-off-by: Trevor Cooper <trevor.cooper@intel.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index bf1b0f8..9d29000 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit bf1b0f81b1c79729433faa2bbf35a3cd7478066b
+Subproject commit 9d2900035923bf307477c5b4b8dc423ba1b2086f