Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "Fixes missing ramdisk and kernel in rpm"
  - Fixes missing ramdisk and kernel in rpm

    Change-Id: I970c79dc2a558af3c904d3b19218da53c98378d1
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index b9f63d5..d21460f 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit b9f63d58a83e18dd221be13348e585533eedcedc
+Subproject commit d21460f3adaa6e454ee52b27a837f9d7e0ea7819