This commit adds the initial infrastructure for building accelerated simulation components.
- Adds the CUDA_ENABLE option and logic to find the CUDA toolkit.
- Adds the CHANNEL_SSE option to enable SSE-specific code paths.
- Sets required properties on the SIMU target to allow linking with CUDA-compiled objects.
- Creates the initial oai_cuda.h header for the public API.
Most (but not all) physical simulators are defined under
openair1/SIMULATION/. Defining physical simulators below there seems to
be the more "obvious" directory anyway, as the physical simulators are
openair1/SIMULATION/tests
Phy(L1) Sim tests => PhySim (tests)