video: ARM CLCD: fix Vexpress regression

The CLCD does not come up on Versatile Express as it does not
(currently) have a syscon node for controlling the block apart
from the CLCD itself. Make sure the .init() function can bail
out without an error making it probe again.

Reported-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Amit Pundir <amit.pundir@linaro.org>
Tested-by: Nicolae Rosia <nicolae_rosia@mentor.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>