Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Fix NSB NFVi metrics accuracy"
  - Fix NSB NFVi metrics accuracy

    JIRA: YARDSTICK-1212

    Change-Id: Ic4d4a3c00e4e278f4de06cc176ff663892895569
    Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index c5ea8f6..e07163f 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit c5ea8f6449bb80e239753fe954f9f02b728777dd
+Subproject commit e07163f9d5ef6060112792caf08678943dc2fe11