Only python and numpy implementations available as reference

[AlexanderKalistratov]

python and numpy implementations for deformable convolution (#168) are too slow and fails by timeout and shouldn't be used as reference. Instead sycl should be used as reference.

But at the moment dpbench doesn't allow to choose reference implementation.

[ZzEeKkAa]

Sorry, this feature is not documented, but you can add reference_implementation_postfix key in benchmark configuration.

P.S.: reference implementation will be run in the same thread as implementation, so make sure it does not introduce conflicts.
P.S.2: sycl implementation is not working on windows, so if you set it as reference - it may prevent it from working on windows.
P.S.3: you can use --no-validate flag for run command