Remove obsolete OpenSSL hacks for IDEA crypto.

We have some hacks in the ports tree to detect or to unconditionally disable
IDEA crypto support. These hacks existed because OpenSSL in FreeBSD 9.3 and
earlier was shipped without IDEA support by default but we were allowed to
enable it via WITH_IDEA src.conf(5) option.

https://www.freebsd.org/cgi/man.cgi?query=src.conf&manpath=FreeBSD+9.3-RELEASE

Therefore, we had to implement some hacks to support three different cases,
i.e., a) 9.3 and earlier without IDEA crypto (default), b) 9.3 and earlier
with IDEA crypto (via WITH_IDEA src.conf option), and c) 10.0 and later with
unconditional IDEA support. Now we can safely remove them because 9.3 and
earlier is no longer supported.

PR: 218233
Exp-Run by: antoine
Approved by: antoine (portmgr)