Move the version function declarations to include/openssl/crypto.h

Move the version function declarations to include/openssl/crypto.h

include/openssl/crypto.h is where older similar functions already
live, and since opensslv.h became a template, it's no longer useful
for parsing by util/mknum.pl.

Affected declarations:

 unsigned int OPENSSL_version_major(void);
 unsigned int OPENSSL_version_minor(void);
 unsigned int OPENSSL_version_patch(void);
 const char *OPENSSL_version_pre_release(void);
 const char *OPENSSL_version_build_metadata(void);

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10205)