Support SUNDIALS option in `BuildParFlow.cmake`

[kvrigor]

parflow/parflow@5ae8346 introduced the option to replace ParFlow's internal KINSOL solver with the one from the SUNDIALS library:

KINSOL Solver

There are two compile options for the KINSOL solver used by ParFlow. The current default is to use an old version of KINSOL that is embedded in ParFlow. The newer option is to use KINSOL from the SUNDIALS package. To use the SUNDIALS package you will need to have a SUNDIALS install that includes KINSOL and specify during the CMake configuration:

  -DSUNDIALS_ROOT=<directory of the location of sundials install>

The GitHub repository for SUNDIALS has downloads and build instructions.

This new ParFlow feature might be interesting for TSMP2 testing and benchmarking purposes.