new ports: sysutils/rocr and sysutils/roct

roct is the ROC thunk interface and rocr is the ROCm platform runtime.
Together these form the userspace partners to the amdkfd compute driver.
Hence, in the current absence of a working amdkfd on FreeBSD, these ports do
not function yet. They are integrated to facilitate integration of amdkfd and
test it as part of the LinuxKPI-based DRM.

Note that these ports are for the time being based off my forks with FreeBSD
bringup bits, I'll work with the corresponding upstream teams to get patches
reviewed and integrated.

Limit these ports to amd64, as even our upstream does not support anything but
that for the time being.

Version numbers correspond to the overall ROCm release, currently 1.9.1.