generator: Kconfig: implemented a basic Kconfig generator.

kconfig_gen generates a basic Kconfig file using the input JSON
based config file and an output filename.

Signed-off-by: Michel Megens <dev@michelmegens.net>
git: added Kconfig entry to the .gitignore

Kconfig files generated durings tests should never end up in the
SCM accidentily.

Signed-off-by: Michel Megens <dev@michelmegens.net>
pconf: config: the core module will be default enabled.

The default module should be described in a key called PConf_driver_info
and this key will be enabled as a module by default if building in tree.

Signed-off-by: Michel Megens <dev@michelmegens.net>