Add 60 and 30km ncdata files for analytic ICs w/o topography

These files have been generated using MPAS-A init-atmosphere core for
CAM-MPAS grids (case 13) based on standard 60 and 30km MPAS meshes.

Also add default values for mpasa60 and mpasa30 hgrids. Needed default
values for mpas_dt and mpas_len_disp since they are affected by hgrids.

bld/namelist_files/namelist_defaults_cam.xml

@@ -48,6 +48,8 @@
 <ncdata hgrid="mpasa120" nlev="32" analytic_ic="1" >atm/cam/inic/mpas/mpasa120_L32_notopo_coords_c201216.nc</ncdata>
 <ncdata hgrid="mpasa120" nlev="32" analytic_ic="1" phys="cam6" >atm/cam/inic/mpas/mpasa120_L32_topo_coords_c201022.nc</ncdata>
 <ncdata hgrid="mpasa120" nlev="32" analytic_ic="1" phys="cam_dev" >atm/cam/inic/mpas/mpasa120_L32_topo_coords_c201022.nc</ncdata>
+<ncdata hgrid="mpasa60"  nlev="32" analytic_ic="1" >atm/cam/inic/mpas/mpasa60_L32_notopo_coords_c230707.nc</ncdata>
+<ncdata hgrid="mpasa30"  nlev="32" analytic_ic="1" >atm/cam/inic/mpas/mpasa30_L32_notopo_coords_c230707.nc</ncdata>
 
 <!-- Files with initial conditions -->
 <ncdata dyn="fv"  hgrid="0.23x0.31" nlev="26" ic_ymd="101"      >atm/cam/inic/fv/cami_0000-01-01_0.23x0.31_L26_c100513.nc</ncdata>
@@ -3115,6 +3117,8 @@
 <mpas_time_integration_order  > 2 </mpas_time_integration_order>
 <mpas_dt                      > 1800.0D0 </mpas_dt>
 <mpas_dt hgrid="mpasa120"     >  900.0D0 </mpas_dt>
+<mpas_dt hgrid="mpasa60"      >  450.0D0 </mpas_dt>
+<mpas_dt hgrid="mpasa30"      >  225.0D0 </mpas_dt>
 
 <mpas_split_dynamics_transport>.true.</mpas_split_dynamics_transport>
 <mpas_number_of_sub_steps     > 2 </mpas_number_of_sub_steps>
@@ -3129,6 +3133,8 @@
 
 <mpas_len_disp hgrid="mpasa480">480000.0D0</mpas_len_disp>
 <mpas_len_disp hgrid="mpasa120">120000.0D0</mpas_len_disp>
+<mpas_len_disp hgrid="mpasa60">  60000.0D0</mpas_len_disp>
+<mpas_len_disp hgrid="mpasa30">  30000.0D0</mpas_len_disp>
 
 <mpas_visc4_2dsmag            > 0.05D0 </mpas_visc4_2dsmag>
 <mpas_del4u_div_factor        > 10.0D0 </mpas_del4u_div_factor>