[openssl/openssl] 28a5aa: Add documentation for the OPENSSL_gmtime functions

[Todd Short]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: 28a5aa0cbdddfdf4d82a437d72407d4f52d4e54a
      https://github.com/openssl/openssl/commit/28a5aa0cbdddfdf4d82a437d72407d4f52d4e54a
  Author: Todd Short <tshort at akamai.com>
  Date:   2022-09-26 (Mon, 26 Sep 2022)

  Changed paths:
    M doc/build.info
    A doc/man3/OPENSSL_gmtime.pod
    M util/missingcrypto.txt

  Log Message:
  -----------
  Add documentation for the OPENSSL_gmtime functions

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19257)