contrib/gitdm: add Simon to individual contributors

Please confirm this is the correct mapping for you.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Simon Safar <simon@simonsafar.com>
Message-Id: <20220926134609.3301945-2-alex.bennee@linaro.org>

contrib/gitdm/group-map-individuals

@@ -36,3 +36,4 @@ chetan4windows@gmail.com
 akihiko.odaki@gmail.com
 paul@nowt.org
 git@xen0n.name
+simon@simonsafar.com