mailmap: add entries for Mathieu Othacehe

Add my gnu.org mail address.

Link: https://lkml.kernel.org/r/20231223144226.25740-1-othacehe@gnu.org
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Cc: Bjorn Andersson <quic_bjorande@quicinc.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Matt Ranostay <matt@ranostay.sg>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Mathieu Othacehe

.mailmap

@@ -370,7 +370,7 @@ Martin Kepplinger <martink@posteo.de> <martin.kepplinger@ginzinger.com>
 Martin Kepplinger <martink@posteo.de> <martin.kepplinger@puri.sm>
 Martin Kepplinger <martink@posteo.de> <martin.kepplinger@theobroma-systems.com>
 Martyna Szapar-Mudlaw <martyna.szapar-mudlaw@linux.intel.com> <martyna.szapar-mudlaw@intel.com>
-Mathieu Othacehe <m.othacehe@gmail.com>
+Mathieu Othacehe <m.othacehe@gmail.com> <othacehe@gnu.org>
 Mat Martineau <martineau@kernel.org> <mathew.j.martineau@linux.intel.com>
 Mat Martineau <martineau@kernel.org> <mathewm@codeaurora.org>
 Matthew Wilcox <willy@infradead.org> <matthew.r.wilcox@intel.com>