regression_4006: explicit ECDSA tests are SHA1 based

Explicitly use algorithm ID TEE_ALG_TEE_ECDSA_SHA1 for current ECDSA
tests in regression_4006 instead of old API ID TEE_ALG_ECDSA_P*
that are deprecated in GP TEE Internal Core API v1.3.1. This change
is required to allow changes in OP-TEE OS where TEE_ALG_ECDSA_P*
will no more straight alias IDs TEE_ALG_ECDSA_SHA* because the GP TEE
specification says ECDSA key size is not related to the hash algorithm.

Duplicate however few tests using legacy _OPTEE_ALG_ECDSA_P* for testing
these OP-TEE specific still supported IDs.

The key size for the related tests is found from the NIST key data
material used in the test instead of the crypto algorithm ID when it
does not provide this information.

By the way, add an explicit inline comment telling why we currently
force SHA1 hashing for TEE_MAIN_ALGO_ECDSA regression_4006 tests.

Signed-off-by: Etienne Carriere <[email protected]>