Update git submodules

* Update docs/submodules/sdc.git from branch 'master'
  to c8f88d9b496e8f10179bfc26a09a27386d156d47
  - Fix potential NullPointer in SchemaFileImport

    While reading the YAML to import, if the content was missing
    the entry node_types it was causing a NullPointerException.
    Also the exception was being suppressed, making very difficult
    to understand what happened.

    Change-Id: I44badbee1c739ddf6db08b4e518adb33c430fa84
    Issue-ID: SDC-3070
    Signed-off-by: andre.schmid <andre.schmid@est.tech>

diff --git a/docs/submodules/sdc.git b/docs/submodules/sdc.git
index 988c286..c8f88d9 160000 (submodule)
--- a/docs/submodules/sdc.git
+++ b/docs/submodules/sdc.git
@@ -1 +1 @@
-Subproject commit 988c286efe09c01db6f2e41f0ce4b2f49f92d1a6
+Subproject commit c8f88d9b496e8f10179bfc26a09a27386d156d47