MAINTAINERS: Add the CI-related doc files to the CI section

The docs/devel/ci* were not covered yet, add them to MAINTAINERS
so that the right people are put on CC: for related patches.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/MAINTAINERS b/MAINTAINERS
index 0f9c4b2..de2ef5a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3918,6 +3918,7 @@
 F: .gitlab-ci.yml
 F: .gitlab-ci.d/
 F: .travis.yml
+F: docs/devel/ci*
 F: scripts/ci/
 F: tests/docker/
 F: tests/vm/