CMakeLists.txt: Workaround openssl deprecation of HMAC and CMAC primitives

Following commits mark CMAC and HMAC primitives deprecated:

  commit a6d572e60120e0ffb42aece17a085f0fed1b8f6f
  Author: Pauli <paul.dale@oracle.com>
  Date:   Tue Jan 14 10:59:11 2020 +1000

      Deprecate the low level CMAC functions

  commit dbde4726889a19af0a718fe9c5542f39c81acbd3
  Author: Pauli <paul.dale@oracle.com>
  Date:   Tue Jan 14 12:11:50 2020 +1000

      Deprecate the low level HMAC functions

Add `-Wno-error=deprecated-declarations' to appropriate targets.

References:
  https://github.com/openssl/openssl/commit/a6d572e601
  https://github.com/openssl/openssl/commit/dbde472688