mailmap: Add entry for Rodrigo Siqueira

Map all of my previously used email addresses to my @igalia.com address.

Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <siqueira@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: rodrigosiqueira

.mailmap

@@ -608,6 +608,8 @@ Richard Leitner <richard.leitner@linux.dev> <me@g0hl1n.net>
 Richard Leitner <richard.leitner@linux.dev> <richard.leitner@skidata.com>
 Robert Foss <rfoss@kernel.org> <robert.foss@linaro.org>
 Rocky Liao <quic_rjliao@quicinc.com> <rjliao@codeaurora.org>
+Rodrigo Siqueira <siqueira@igalia.com> <rodrigosiqueiramelo@gmail.com>
+Rodrigo Siqueira <siqueira@igalia.com> <Rodrigo.Siqueira@amd.com>
 Roman Gushchin <roman.gushchin@linux.dev> <guro@fb.com>
 Roman Gushchin <roman.gushchin@linux.dev> <guroan@gmail.com>
 Roman Gushchin <roman.gushchin@linux.dev> <klamm@yandex-team.ru>