Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Fix NSB PROX L3FWD dropping packets"
  - Fix NSB PROX L3FWD dropping packets

    JIRA: YARDSTICK-1037

    Adjusted number of RX/TX descriptors to 2048, instead of default 256,
    in order to cope with interrupts during which no packets are received
    by the core, which results in the NIC dropping packets when it gets out
    of available descriptors to buffer them.
    Also adjusted mempool size, because more descriptors need more mbufs.

    This change aligns L3FWD test case with other test cases, for which
    number of RX/TX descriptors is already set to 2048.

    Change-Id: I11378c078398aca799295b619bb3d14dbee04ca3
    Signed-off-by: Patrice Buriez <patrice.buriez@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0ddf777..b3f66cb 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0ddf777a4d0621f19ad2017292b8d2c548d5e038
+Subproject commit b3f66cbe27bc9931e979eee83bcae2253846c5dd