selftests: tls: add missing AES256-GCM cipher

mainline inclusion
from mainline-v5.16-rc5
commit 13bf99ab
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I56S5K?from=project-issue

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=13bf99ab2130783e2b1988ef415585e3af7df97b



--------------------------------

Add tests for TLSv1.2 and TLSv1.3 with AES256-GCM cipher

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>