.mailmap: specify spelling for James Zhu

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/1999>
diff --git a/.mailmap b/.mailmap
index 6f7c73b..d423c8d 100644
--- a/.mailmap
+++ b/.mailmap
@@ -266,6 +266,8 @@
 
 James Legg <jlegg@feralinteractive.com> <lankyleggy@gmail.com>
 
+James Zhu <James.Zhu@amd.com>
+
 Jan Vesely <jano.vesely@gmail.com> Jan Vesely <jan.vesely@rutgers.edu>
 
 Jason Ekstrand <jason@jlekstrand.net> <jason.ekstrand@intel.com>