Update git submodules

* Update docs/submodules/nfvbench from branch 'master'
  - [NFVBENCH-20] Use updated kernel for the image

    1. Update testpmd to DPDK 17.05.2;
    2. Update VPP to 17.07-30;
    3. Fix the script to use the new kernel;

    buildvm

    Change-Id: Icd62ff1c383598db4f80bc9b36794ff0f8d0e56c
    Signed-off-by: Yichen Wang <yicwang@cisco.com>

diff --git a/docs/submodules/nfvbench b/docs/submodules/nfvbench
index 46f94ba..d05d0c0 160000 (submodule)
--- a/docs/submodules/nfvbench
+++ b/docs/submodules/nfvbench
@@ -1 +1 @@
-Subproject commit 46f94badf4feadcf64f57071d99f7ccd86f19ed9
+Subproject commit d05d0c07856534e439792f86e1c1885850e9ad44