ciflow/trunk/185571: xpu: match dpclang SYCL_LIBRARY setting with icpx

With icpx we set SYCL_LIBRARY as a value returned by find_library().
This commit aligns dpclang path behavior with that which is needed to
meet existing expectations when building some pytorch code such as kineto.

This commit builds on top of (00884ed "xpu: enable dpclang sycl compiler")
and additionally allows to build pytorch for XPU based on fully open source
stack with enabled kineto profiling.

PTI library required for XPU kineto can be built from the following sources:

• https://github.com/intel/pti-gpu

Validated build command line:

XPU_SYCL_COMPILER=dpclang USE_KINETO=1 USE_ONEMKL_XPU=0 \
      python3 setup.py develop

Enabled kineto build verified by running test/profiler/test_xpu_profiler.py,
all tests passing.

Signed-off-by: Dmitry Rogozhkin [email protected]