.mailmap: Fix Heinrich's xypron.glpk@gmx.de record

There is one issue with Heinrich xypron.glpk@gmx.de <xypron.glpk@gmx.de>
record which should be specifically grouped with his name.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

.mailmap

@@ -28,6 +28,7 @@ Boris Brezillon <bbrezillon@kernel.org> <boris.brezillon@free-electrons.com>
 Dirk Behme <dirk.behme@googlemail.com>
 Fabio Estevam <fabio.estevam@nxp.com>
 Heinrich Schuchardt <xypron.glpk@gmx.de> <heinrich.schuchardt@canonical.com>
+Heinrich Schuchardt <xypron.glpk@gmx.de> xypron.glpk@gmx.de <xypron.glpk@gmx.de>
 Jagan Teki <402jagan@gmail.com>
 Jagan Teki <jaganna@gmail.com>
 Jagan Teki <jaganna@xilinx.com>