Update git submodules

* Update docs/submodules/doctor from branch 'master'
  - Merge "add maintenance detailed spec"
  - add maintenance detailed spec

    JIRA: DOCTOR-52

    Change-Id: I43c2d224fcd188946049d89fe266c541ea268dea
    Signed-off-by: Tomi Juvonen <tomi.juvonen@nokia.com>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index 5b1401a..c9fb520 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit 5b1401a9194daae197a8f5ae534b9a37dd483eac
+Subproject commit c9fb5207df1a3aa579d86f413587ec47c41063af