scripts: kconfig: Add support for wildcards and globbing

Some projects use wildcards when sourcing a Kconfig file. Add
support for globbing the files that match the wildcards and process
them one by one.

Origin: https://github.com/carlescufi/Kconfiglib/tree/zephyr



Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>