Don't use this, it doesn't work yet. Thoughs welcome.
Like: We should probably use the sym->text and not fiddle with the name since
the name looses information ('_' != '-' in host-fakeroot). This would not
be too robust, i fear, since the name can contain additional, arbitrary info.
Also, the real 'depends' are a little bit ugly in kconfig. There doesn't seem
to be a nice property that holds reverse deps that are only contain selected
symbols.
Thoughts?
This also provides a nice up-to-date filestamp if something got reconfigured (e.g. c++ support got toggled) that can be used in the future to depend accordingly.