[BUG] Cannot disable TRT on device doesn't have GPU

[ahuizxc]

cmake -G Ninja -DDNNL_COMPILER=/host/gcc10/bin/gcc

then i get

-- Found GCC10: /host/gcc10/bin/gcc, build odla_dnnl with bf16 support!
-- Popart library not found, skip building ODLA for Popart
-- The CUDA compiler identification is unknown
CMake Error at ODLA/platforms/tensorrt/CMakeLists.txt:17 (enable_language):
  No CMAKE_CUDA_COMPILER could be found.

  Tell CMake where to find the compiler by setting either the environment
  variable "CUDACXX" or the CMake cache entry CMAKE_CUDA_COMPILER to the full
  path to the compiler, or to the compiler name if it is in the PATH.