selftests/sgx: Migrate to kselftest harness

mainline inclusion
from mainline-v5.14-rc1
commit 235d1c9c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SIGI


CVE: NA

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

Migrate to kselftest harness. Use a fixture test with enclave initialized
and de-initialized for each of the existing three tests, in other words:

1. One FIXTURE() for managing the enclave life-cycle.
2. Three TEST_F()'s, one for each test case.

Dump lines of /proc/self/maps matching "sgx" in FIXTURE_SETUP() as this
can be very useful debugging information later on.

Amended commit log:
This migration changes the output of this test. Instead of skipping
the tests if open /dev/sgx_enclave fails, it will run all the tests
and report failures on all of them.
Shuah Khan <skhan@linuxfoundation.org>

Intel-SIG: commit 235d1c9c selftests/sgx: Migrate to kselftest harness
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>