[OpenCL] Fixes SYCL profiler tests (#141)

The profiler relies heavily on the canonical device being listed in the
TFProf nodes, which is only set for those devices which return True from
CountAsCPUTime, so we need this to return True for SYCL device nodes
too. The check for whether the node will run on an Accelerator comes
from IsPlacedOnAccelerator.