[U-Boot] [RFC PATCH] kconfig: introduce kconfig for UBI

[Andrew F. Davis]

BTW, the following addresses that bounce should be removed from wherever
you found them or added to .get_maintainer.ignore if they are part of
old commits:

Bo Shen <voice.shen at atmel.com>
Albert ARIBAUD <albert-u-boot at aribaud.net>
Gerald Kerma <dreagle at doukki.net>
Karl Beldan <kbeldan at baylibre.com>
Vaibhav Hiremath <hvaibhav at ti.com>
Sudhakar Rajashekhara <sudhakar.raj at ti.com>