Add missing dependency on core_physics_mmm in core_atmosphere/physics/Makefile

[mgduda]

This PR corrects parallel build failures in the atmosphere core by adding a missing dependency on core_physics_mmm in src/core_atmosphere/physics/Makefile. The core_physics_wrf build target should depend on core_physics_mmm, since compilation of modules in the physics_wrf directory depends on successful compilation of modules in the physics_mmm directory.

[ldfowler58]

In MPAS-Dev:develop:

in ./physics/Makefile, we added -I./physics_mmm at the bottom of the file. in ./physics/physics_wrf/Makefile, we added -I../physics_mmm at the bottom of the file.

so I do not understand why we need to modify line 55 to core_physics_wrf: core_physics_init core_physics_mmm

Thanks.

[gdicker1]

@ldfowler58 this has to do with GNU Make and the compilation process, instead of compilation flags. So far, builds have succeeded because core_physics_mmm just happens to build before core_physics_wrf. My recent parallel build attempts showed me that this isn't guaranteed. Adding this prerequisite would guarantee the compilation order.