.mailmap: add an alias for Yaakov Selkowitz

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/1999>
diff --git a/.mailmap b/.mailmap
index 681459f..1f125c9 100644
--- a/.mailmap
+++ b/.mailmap
@@ -619,6 +619,8 @@
 
 Vivek Kasireddy <vivek.kasireddy@intel.com>
 
+Yaakov Selkowitz <yselkowi@redhat.com> <yselkowitz@users.sourceforge.net>
+
 Wladimir J. van der Laan <laanwj@gmail.com>
 
 Xavier Bouchoux <xavierb@gmail.com>