Update git submodules

* Update docs/submodules/yardstick from branch 'stable/gambia'
  - Configure n_rxq DPDK port option when adding the port

    On some platform, setting n_rxq option on port separately
    does not work well and causes issues like port link down,
    so changed the logic to set n_rxq DPDK port option during
    adding the port to the bridge which help to resolve
    the problem.

    JIRA: YARDSTICK-1463

    Change-Id: Icdb064153a38afd53b835de8742e6fcef08f66bb
    Signed-off-by: Mytnyk, Volodymyr <volodymyrx.mytnyk@intel.com>
    (cherry picked from commit adcc29e56130f0f047b99528ce72b6f149643da7)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index e0b7c0a..02aa6ce 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit e0b7c0ad95d44eea4db4a3fb532f51688c97c8fc
+Subproject commit 02aa6ce47db11f92bc343307fb7fe67dcc86f773