Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - Freeze requirements for Euphrates

    Change-Id: Ifbdd773235497373eba8ecc44b21c207441fe407
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index 28fd595..583d718 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit 28fd59520f3ef9a895e2fcb43f599011b6589ac1
+Subproject commit 583d7181b15ae6f8d6319c36bad6fd043f47c89f