fs: ubifs: rework logging ...

By default UBIFS is very verbose. Decrease the verbosity, turn
printf messages into ubifs_ messages and add device parameters
for the values which are not printed anymore.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: Add ubifs support ...

This adds ubifs support from u-boot-2013.07. This is taken
mostly as-is, only the necessary adjustments to attach to the
barebox fs layer have been made.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>