crypto/openssl: remove autogenerated files

These files contain build host paths and other configuration details
that can be regenerated via the standard vendor import process. Don't
clutter up the FreeBSD tree with these files.

Add the paths to .gitignore to prevent them from accidentally being
added in a future update.

MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D53044

Conflicts:
crypto/openssl/libcrypto.pc
crypto/openssl/libssl.pc
crypto/openssl/openssl.pc

(cherry picked from commit d271d2ce152435b14e309bd8b25f47a0f4a2040f)