Update git submodules

* Update docs/submodules/apex from branch 'stable/euphrates'
  - Adds Calipso scenario

    Change-Id: Icc8a23e49c9ccc011481f6b97599d4f75873ebb1
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit 1a824cf106f1996f184a7f699c754a7b72c501be)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 5bbba78..17c64de 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 5bbba78faa198976be1a1a5437d39cfa5059d896
+Subproject commit 17c64de8f2d9c86c0f80df8dddf7831210f5234a