Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Fix broken clean due to virtualbmc change

    Apex clean is failing when trying to clean vbmcs because the function
    was changed in new virtualbmc version. Adding the working version to our
    constraints.

    JIRA: APEX-631

    Change-Id: I62971183669e4a51e841d79892e78b10ea380a1e
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index beafc8f..7bbbc90 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit beafc8f4ede72ddb1d2abc2eaff14f9c954bf3fd
+Subproject commit 7bbbc905908be356fd1cf2f869b43d7e4d87c12b