docs(maintainers): remove a maintainer for MediaTek SoCs

Change-Id: I56649f80de0a02919befcb42e15847ceb37b1308
diff --git a/docs/about/maintainers.rst b/docs/about/maintainers.rst
index 66ec176..7753334 100644
--- a/docs/about/maintainers.rst
+++ b/docs/about/maintainers.rst
@@ -577,8 +577,6 @@
 
 MediaTek platform ports
 ^^^^^^^^^^^^^^^^^^^^^^^
-:|M|: Rex-BC Chen <rex-bc.chen@mediatek.com>
-:|G|: `mtk-rex-bc-chen`_
 :|M|: Leon Chen <leon.chen@mediatek.com>
 :|G|: `leon-chen-mtk`_
 :|M|: Jason-CH Chen <jason-ch.chen@mediatek.com>
@@ -1020,7 +1018,6 @@
 .. _michalsimek: https://github.com/michalsimek
 .. _mmind: https://github.com/mmind
 .. _MrVan: https://github.com/MrVan
-.. _mtk-rex-bc-chen: https://github.com/mtk-rex-bc-chen
 .. _Neal-liu: https://github.com/neal-liu
 .. _niej: https://github.com/niej
 .. _nmenon: https://github.com/nmenon