Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 64c6d53bea60fdeabd01aa9b114567c4cb12f3fe
  - Merge "update CSMF bpmn to adpter EXT-API"
  - update CSMF bpmn to adpter EXT-API
    
    Issue-ID: SO-2919
    
    Signed-off-by: hetengjiao <hetengjiao@chinamobile.com>
    Change-Id: Ie506e13c55c9745653471908cb69d59d85c10cbb
    
diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 5dd3084..64c6d53 160000
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 5dd30849655e5a218c63d6c3855e8916399e49e7
+Subproject commit 64c6d53bea60fdeabd01aa9b114567c4cb12f3fe