Enabled installing CUDA from the NVIDIA repository. This is enabled by setting the variable use_nvidia_cuda_repo to true. A list of cuda and cudnn packages should be provided to the role when using this setting (i.e. the default cudnn packages are not likely to work).
Change also enables upgrading of CUDA when installed via the NVIDIA repository. The variable upgrade_cuda must be set to true and updated packages supplied via the cuda and cudnn package variables.