CMake: Use SUITESPARSE_INCLUDEDIR in more places.

[mmuetzel]

Also, don't double quote generator expressions. (I don't recall why I did that in the first place...)

The remaining place where CMAKE_INSTALL_INCLUDEDIR is still used is in GraphBLAS/cpu_features/CMakeLists.txt. I'm not sure what that is and left it alone.

[DrTimothyAldenDavis]

The cpu_features folder is an exact copy of the original Google repo for that package, but I don't use the cpu_features build system itself to create a cpu_features library. I compile the code from the GraphBLAS cmake. So the cpu_features/CMakeLists.txt file is unused. Same thing with CHOLMOD/SuiteSparse_metis/CMakelists.txt

[mmuetzel]

So the cpu_features/CMakeLists.txt file is unused.

In that case, the changes from this PR should be complete when it comes to the include directory in the interface of the CMake targets.

[DrTimothyAldenDavis]

Looks good.

Removing the extraneous double quotes is a good idea. I was confused by them since the spurious report from SuiteSparse_GPURuntime had no double quotes but the other places had it, so I thought that error was from missing a required double quote.

[DrTimothyAldenDavis]

Works great -- thanks! The Example package now compiles on my desktop when using CUDA.