According the the definition in ictce.py, it includes FFTW.

So, should we throw an error here mentioning that the ictce being used apparently features a IMKL without interfaces, as opposed to an info/warning message?
Do we have a good reason to set interfaces to `False`, like we do now in https://github.com/hpcugent/easybuild-easyconfigs/blob/master/easybuild/easyconfigs/i/imkl/imkl-10.2.6.038.eb?