fixed find package CUDA for cross-compilation

replaced find_host_package with find_package and
set CMAKE_FIND_ROOT_PATH_MODE_LIBRARY to BOTH, because NEVER 
doesn't work for CUDA_CUDA_LIBRARY, which is located in 
/usr/arm-linux-gnueabihf/lib/libcuda.so for ARM
Merge pull request #1714 from jet47:find-cuda-fix