Some AP's keep NULL-padding at the end of some variable length WPS
Attributes. This is not as par the WPS2.0 specs, but to avoid interop
issues, ignore the padding by reducing the attribute length by 1.
Move supplicant to idf and do following refactoring:
1. Make the folder structure consitent with supplicant upstream
2. Remove duplicated header files and minimize the public header files
3. Refactor for WiFi/supplicant interfaces