devel/erlang-cl: update to 1.2.4

While here, patch this port's build scripts to actually build the
opencl NIF (Native Implemented Function) - the build system didn't know
about FreeBSD and failed when building cl_nif.so, but the error went
unnoticed. Without this object, erlang-cl cannot load any CL function
(in our case, we want to use libOpenCL), which rather defeats the
purpose of this port.

Once we build and install cl_nif.so, we have to depend on devel/ocl-icd
to pull in libOpenCL.

PR: 239178
Approved by: maintainer-timeout (erlang@)