.mailmap: add entry for Tom Lendacky

... for git-shortlog purposes.

Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>