fbdev: offb: fix up missing cleanup.h

In commit 96ee5c57 ("fbdev: offb: replace of_node_put with
__free(device_node)"), __free() was added, but not cleanup.h so it broke
the build.  Fix this up.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/4f4ac35e-e31c-4f67-b809-a5de4d4b273a@roeck-us.net


Fixes: 96ee5c57 ("fbdev: offb: replace of_node_put with __free(device_node)")
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Abdulrasaq Lawani <abdulrasaqolawani@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>