Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Added hw_vif_multiqueue_enabled metadata to the added samplevnfs image in OpenStack.

    Change-Id: Iad1dce6b0d0a1c010aa62f2fdf54c5d0560ed0c7
    Signed-off-by: Maciej Skrocki <maciej.skrocki@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0db8682..c832dd0 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0db868278e13d21998bd677bfc782557d44ab381
+Subproject commit c832dd05f20936734faadcd1ffa1dd8d01d08819