Change two files from NetCDF-4 format to NetCDF-3 (because some machines have trouble with NetCDF-4 in pnetcdf)

There are two files in NetCDF-4 format that the model uses. Copy these files to NetCDF-3 classic format and point
to the new version in the CLM XML database (use nccopy -k classic). There are some machines that have trouble with
reading NetCDF-4 files in pnetcdf.

There are still some NetCDF-4 files for mksurfdata_map, but some of these are required to be in NetCDF-4 format. And we only
support mksurfdata_map and mkmapdata on cheyenne.