ssh: generate SK config file using private cbor and fido2 libs
Specify -lprivatecbor and -lprivatefido2 in OpenSSH's configure.ac, and
pass -I paths to libcbor and libfido2's contrib src location.
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34440