media: imx-pxp: disable LUT block

The LUT block is always configured in bypass mode.

Take it entirely out of the pipeline by disabling it and routing the
data path around the LUT.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>