staging: drm/imx: set second plane base address

Even though we do not enable the hardware double buffering feature
right now, set the second base address pointer (EBA1) as well to
increase robustness.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>