Complete CCPPization of orographic (CAM4) gw drag; move gravity wave parameterizations to atmos_phys.

[jimmielin]

Couldn't find an issue in ESCOMP/CAM.
Regression tests (izumi nag, gnu; derecho intel) pass as of 64_109; will merge up for another round of testing when the tags move further

Purpose of changes (include the issue number and title text for each relevant GitHub issue):

• Move all gravity wave parameterizations to atmos_phys.
• Complete CCPPization of necessary interstitials
• Complete CCPPization of orographic gravity wave drag for CAM4.

Describe any changes made to build system: Add gravity wave drag scheme subdirectory to atmos_phys.

Describe any changes made to the namelist:

• Minor typo fixes; removal of certain unused parameters

List any changes to the defaults for the boundary datasets:

• Topo file for ne3np4 -- not sure where this came from; change was inherited from @jtruesdal

Describe any substantial timing or memory changes: N/A

Code reviewed by:

List all files eliminated:

D       src/physics/cam/gw_common.F90
D       src/physics/cam/gw_convect.F90
D       src/physics/cam/gw_diffusion.F90
D       src/physics/cam/gw_front.F90
D       src/physics/cam/gw_movmtn.F90
D       src/physics/cam/gw_oro.F90
D       src/physics/cam/gw_rdg.F90
D       src/physics/cam/gw_utils.F90
  - moved to atmos_phys, cleaned up, CCPPized, renamed.

D       src/physics/cam/vdiff_lu_solver.F90
  - moved to atmos_phys/to_be_ccppized.

D       src/physics/cam/gw_drag.F90
  - moved to gw_drag_cam and made into a CAM interface to CCPPized subroutines.

List all files added and what they do:

A       src/physics/cam/gw_drag_cam.F90
  - new CAM interface to CCPPized subroutines.

List all existing files that have been modified, and describe the changes:

M       .gitmodules
M       bld/configure
  - add new gw_drag subdir in atmos_phys.

M       bld/namelist_files/namelist_defaults_cam.xml
  - new ne3np4 topo file

M       bld/namelist_files/namelist_definition.xml
M       bld/build-namelist
  - minor typo fixes
  - removal of unused parameters in namelist.

M       src/control/runtime_opts.F90
M       src/physics/cam/physpkg.F90
M       src/physics/cam7/physpkg.F90
  - change to use gw_drag_cam CAM interfaces.

M       src/utils/cam_pio_utils.F90
  - remove trailing whitespace