selftests/sgx: Refine the test enclave to have storage

mainline inclusion
from mainline-v5.14-rc1
commit 22118ce1
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SIGI


CVE: NA

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Extend the enclave to have two operations: ENCL_OP_PUT and ENCL_OP_GET.
ENCL_OP_PUT stores value inside the enclave address space and
ENCL_OP_GET reads it. The internal buffer can be later extended to be
variable size, and allow reclaimer tests.

Intel-SIG: commit 22118ce1 selftests/sgx: Refine the test enclave to have storage
Backport for SGX Foundations support

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Fan Du <fan.du@intel.com> #openEuler_contributor
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Reviewed-by: Bamvor Zhang <bamvor.zhang@suse.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>