Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - Fix link error for documents

    Change-Id: I30197065acbe24d409ba81b289076b3a566b8d46
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index bfd4adc..f066800 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit bfd4adcd8f9720b54d7a785de0909e19f7e3a90b
+Subproject commit f0668006bfd9ede5a275b0b40ef054962e7d8839