[ARM] 3232/1: i.MX Frame Buffer undeclared "dev" variable fix

Patch from Pavel Pisa

Correction of the code broken by update
whole-tree platform devices update.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>