Update git submodules

* Update docs/submodules/bottlenecks from branch 'stable/euphrates'
  - Bottlenecks testpmd scale-up testcase.

    JIRA: BOTTLENECK-205

    This is the script of testpmd scale-up feature testcase.
    we will debug the dashboard.

    Change-Id: I4a6de0e7e1ea7c04639ece78a7b11b75128d8d2f
    Signed-off-by: liyin <liyin11@huawei.com>
    (cherry picked from commit c0dc0572a4bf4bfc308b9d9ff5072468b9995d3c)

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 78dd890..12a7a9b 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 78dd8905f727cdfa1f7ba9fd01908b81bd06ef39
+Subproject commit 12a7a9ba23db5752ca5caa67c7d57741faaf9ecc