rebase demo_cdpSimplePrint.py on the BSD licensed cdpSimplePrint.cu

`examples/demo_cdpSimplePrint.py` comes with a problematic license:
```
* Adapted from NVIDIA's "cdpSimplePrint - Simple Print (CUDA Dynamic Parallelism)" sample
* http://docs.nvidia.com/cuda/cuda-samples/index.html#simple-print--cuda-dynamic-parallelism-
* http://ecee.colorado.edu/~siewerts/extra/code/example_code_archive/a490dmis_code/CUDA/cuda_work/samples/0_Simple/cdpSimplePrint/cdpSimplePrint.cu
*
* From cdpSimplePrint.cu (not sure if this is Ok with NVIDIA's 38-page EULA though...):
* ---------------------------------------------------------------------------
* Copyright 1993-2012 NVIDIA Corporation. All rights reserved.
*
* Please refer to the NVIDIA end user license agreement (EULA) associated
* with this source code for terms and conditions that govern your use of
* this software. Any use, reproduction, disclosure, or distribution of
* this software and related documentation outside the terms of the EULA
* is strictly prohibited.
* ---------------------------------------------------------------------------
```

Fortunately NVIDIA recently released their code samples under the 3-clause BSD license: https://github.com/NVIDIA/cuda-samples

Please rebase that example on the updated free source code https://github.com/NVIDIA/cuda-samples/blob/master/Samples/3_CUDA_Features/cdpSimplePrint/cdpSimplePrint.cu