Need to update README to explain how to verify SM2 with openssl-3.0.0

[docularxu]

Two requests:
1). Need to update README to explain when openssl-3.0.0 is needed and when openssl-1.0 is. At lease it should be noted in README the limitations of using openssl-1.0.
2). Method of how to verify SM2 should be included in README.

In the current README, it said we need 'openssl-1'. Ref:

uadk_engine/README

Line 14 in 50692e4

* OpenSSL: 1.1.1f

However, in the following commit, it said to use sm2, it needs 'openssl-3.0.0'.

commit id: d1938de07ae2342f834c45f082aa7f8ef76c605f
sm2: add support for sm2 algorithm
Support sm2 sign/verf/encrypt/decrypt/keygen.

If test sm2 algorithm, please use openssl-3.0.0
and only speed tools supported.

Test use openssl cmd line:
openssl speed -engine uadk sm2
openssl speed -engine uadk -async-jobs 1 sm2

Signed-off-by: Hui Tang <tanghui20@huawei.com>