Update git submodules

* Update docs/submodules/vswitchperf from branch 'stable/danube'
  - Removed reference to POD 3 since VSPERF POD was moved to POD 12

    Change-Id: Ic278ba90c3174b9f83766861981aeb66320c8963
    Signed-off-by: Trevor Cooper <trevor.cooper@intel.com>
    (cherry picked from commit 0ccb44ca1f90200a2e41f25fcf499074c819002d)

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index 1e00995..fade001 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit 1e00995886720000624145ad181ea70ac97a233a
+Subproject commit fade0012b58649f95bd42d9384235c86cb996543