mailmap: update email address for Muhammad Usama Anjum

Add updated email address.

Link: https://lkml.kernel.org/r/20260310171757.3970390-1-usama.anjum@arm.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Carlos Bilbao <carlos.bilbao@kernel.org>
Cc: Hans Verkuil <hverkuil@kernel.org>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Martin Kepplinger <martink@posteo.de>
Cc: Shannon Nelson <sln@onemain.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Muhammad Usama Anjum

.mailmap

@@ -587,6 +587,7 @@ Morten Welinder <terra@gnome.org>
 Morten Welinder <welinder@anemone.rentec.com>
 Morten Welinder <welinder@darter.rentec.com>
 Morten Welinder <welinder@troll.com>
+Muhammad Usama Anjum <usama.anjum@arm.com> <usama.anjum@collabora.com>
 Mukesh Ojha <quic_mojha@quicinc.com> <mojha@codeaurora.org>
 Muna Sinada <quic_msinada@quicinc.com> <msinada@codeaurora.org>
 Murali Nalajala <quic_mnalajal@quicinc.com> <mnalajal@codeaurora.org>