OpenSSL assumes the same value for AT_HWCAP at Linux
So it ends up calling elf_auxv_info() with AT_CANARY which
returns ENOENT, and all acceleration features are disabled.

With this, my ARM64 test machine, the benchmark
openssl speed -evp aes-256-gcm is nearly 20x faster
going from 100 MB/sec to 2000 MB/sec

Also update the configure scripts to detect arm64-*-freebsd
rather than using BSD-generic32

PR: 259937
Sponsored by: Klara Inc.