Correct diagnostic coordinate interpolation scheme

The interpolation scheme for state-dependent diagnostic coordinates
was incorrectly registering as the same parameter as the main model.
This meant it was never possible to change the interpolation scheme
from the default (which was not the same as the main model).

Fix registers the generated parameter name which was always computed
but not used. A typical example of the generated parameter is
"DIAG_COORD_INTERP_SCHEME_RHO2".

src/ALE/MOM_regridding.F90

@@ -263,7 +263,7 @@ subroutine initialize_regridding(CS, GV, US, max_depth, param_file, mdl, coord_m
       param_name = create_coord_param(param_prefix, "INTERP_SCHEME", param_suffix)
       string2 = 'PPM_H4' ! Default for diagnostics
     endif
-    call get_param(param_file, mdl, "INTERPOLATION_SCHEME", string, &
+    call get_param(param_file, mdl, param_name, string, &
                  "This sets the interpolation scheme to use to "//&
                  "determine the new grid. These parameters are "//&
                  "only relevant when REGRIDDING_COORDINATE_MODE is "//&