Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Small correction in docs.

    Change-Id: Iec9a401759de5953d4a8ca05c4f1c32b163343ba
    Signed-off-by: Taseer Ahmed <taseer94@gmail.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 16821de..6ea9c7c 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 16821de4807132ab784926e21059d793e36667ce
+Subproject commit 6ea9c7cca9b137f049362a27369edef43470b907