Zephyr module uses `\` in path on windows when creating Kconfig files

[tejlmand]

The script zephyr_modules.py uses os.path.abspath when generating Kconfig include files for windows.

This causes the generated file to contain path like:

osource "c:\projets\..."

cause the load to fail in windows.

Instead posix style paths should be used.

[ulfalizer]

@tejlmand
How does it fail? Kconfiglib should be able to deal with Windows paths.

[ulfalizer]

Oh, wait, I realized how it fails. "\p" is transformed to just "p", due to how escaping works in strings in Kconfig.