Build file templates: look at *all* defines

When looking at configured macro definitions, we must look at both
what comes from the config target AND what comes from user
configuration.

Fixes #7396

Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/7402)

(cherry picked from commit 92ebf6c4c21ff4b41ba1fd69af74b2039e138114)