Check your environment variable

	OLC_ICD_VENODRDIR

On FreeBSD, this is set to 

	OCL_ICD_VENDORDIR=/usr/local/etc/OpenCL/vendors

The OCL_ICD_VENDORDIR 
(ICD = Installable Client Driver) holds the platform
specific driver configuration files (i.e Intel,
nVidia, AMD, other OpenCL capable devices).

It could be set globally from your system's shell environemt
setting, for 

csh in /etc/csh.cshrc:
	setenv OCL_ICD_VENDORDIR  /usr/local/etc/OpenCL/vendors

or for sh/bash/ksh and derivatives, /etc/profile:
	export OCL_ICD_VENDORDIR=/usr/local/etc/OpenCL/vendors
