Remove leftovers of the legacy CUDA package

The CUDA package properties and version fallback remained after CUDA
discovery switched to the CUDAToolkit package and no longer had any
effect.

Describe only the CUDAToolkit package.

Change-Id: Icc106a80ec34e078cf4df9fe424e1b0603acd3b6

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d30d7f..337d9f4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -894,17 +894,12 @@
   set(${OUTPUT} "${DESCRIPTION}" PARENT_SCOPE)
 endfunction()
 
-set(CERES_CUDA_VERSION "${CUDA_VERSION}")
-if (CUDAToolkit_VERSION)
-  set(CERES_CUDA_VERSION "${CUDAToolkit_VERSION}")
-endif()
-
 ceres_dependency_description(CERES_ABSL_DESCRIPTION
   "C++ common libraries from Google" "${absl_VERSION}")
 ceres_dependency_description(CERES_BENCHMARK_DESCRIPTION
   "A microbenchmark support library" "${benchmark_VERSION}")
 ceres_dependency_description(CERES_CUDA_DESCRIPTION
-  "NVIDIA CUDA toolkit" "${CERES_CUDA_VERSION}")
+  "NVIDIA CUDA toolkit" "${CUDAToolkit_VERSION}")
 ceres_dependency_description(CERES_CUDSS_DESCRIPTION
   "NVIDIA CUDA sparse solver library" "${cudss_VERSION}")
 ceres_dependency_description(CERES_EIGEN3_DESCRIPTION
@@ -936,10 +931,6 @@
 set_package_properties(BLAS PROPERTIES
   DESCRIPTION "Basic Linear Algebra Subprograms implementation"
   PURPOSE "LAPACK dependency")
-set_package_properties(CUDA PROPERTIES
-  DESCRIPTION "${CERES_CUDA_DESCRIPTION}"
-  URL "https://developer.nvidia.com/cuda-toolkit"
-  PURPOSE "CUDA solver acceleration")
 set_package_properties(CUDAToolkit PROPERTIES
   DESCRIPTION "${CERES_CUDA_DESCRIPTION}"
   URL "https://developer.nvidia.com/cuda-toolkit"