mailmap: update Alex Hung's email address

I am no longer at Canonical and add entry of my personal email address.

Link: https://lkml.kernel.org/r/20221114001302.671897-1-alex.hung@amd.comSigned-off-by: Alex Hung <alexhung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

.mailmap

@@ -29,6 +29,7 @@ Alexandre Belloni <alexandre.belloni@bootlin.com> <alexandre.belloni@free-electr
 Alexei Starovoitov <ast@kernel.org> <alexei.starovoitov@gmail.com>
 Alexei Starovoitov <ast@kernel.org> <ast@fb.com>
 Alexei Starovoitov <ast@kernel.org> <ast@plumgrid.com>
+Alex Hung <alexhung@gmail.com> <alex.hung@canonical.com>
 Alex Shi <alexs@kernel.org> <alex.shi@intel.com>
 Alex Shi <alexs@kernel.org> <alex.shi@linaro.org>
 Alex Shi <alexs@kernel.org> <alex.shi@linux.alibaba.com>