expat: upgrade to 2.4.4

Fixes CVE-2022-23852 and CVE-2022-23990.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 4ed96683)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>