Update the core_atmosphere cmake file to include src/framework

[jim-p-w]

This change adds an include of the src /framework directory when building core-atmosphere.

This is required due to a dependency added in #1359.

This fix was tested by building MPAS-Model core_atmosphere via cmake, using the gnu compiler.
This was also tested by building the mpas-bundle suite via cmake using the gnu compiler.

[amstokely]

Consider adding the following to the framework CMakeLists.txt:

target_include_directories(framework
    INTERFACE
        ${CMAKE_CURRENT_SOURCE_DIR}
)

This will automatically append the framework source directory to the core_atmosphere include path, achieving the same result without relying on relative paths.

[jim-p-w]

Consider adding the following to the framework CMakeLists.txt:
target_include_directories(framework
INTERFACE
${CMAKE_CURRENT_SOURCE_DIR}

Putting the dependency in the framework cmake file sounds much cleaner. I'll make an update.

[jim-p-w]

The src/framework directory is now exported by the framework CMakeLists.txt, as suggested by @amstokely.

[abishekg7]

Looks good to me. Checked that it builds correctly.