Blackfin: defconfigs: update after misc devices defaulted to N

The default value for misc devices was changed from Y to N which
causes problems for mini defconfigs that were relying on this
defaulting to Y.  So update all of the defconfigs accordingly.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>