.mailmap: add a couple of aliases for Suresh Guttula

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/1999>
diff --git a/.mailmap b/.mailmap
index 0baad02..9620ed3 100644
--- a/.mailmap
+++ b/.mailmap
@@ -552,6 +552,9 @@
 Stéphane Marchesin <marcheu@chromium.org> Stephane Marchesin <marchesin@icps.u-strasbg.fr>
 Stéphane Marchesin <marcheu@chromium.org> Stephane Marchesin <stephane.marchesin@gmail.com>
 
+Suresh Guttula <suresh.guttula@amd.com>
+Suresh Guttula <suresh.guttula@amd.com> <Suresh.Guttula@amd.com>
+
 Sven M. Hallberg <pesco@users.sourceforge.net> pesco <pesco>
 
 Tapani Pälli <tapani.palli@intel.com> <tapani.palli@gmail.com>