Unfortunately, the PXP_HW_VERSION register reports the PXP on the i.MX7D
and on the i.MX6ULL as version 3.0, although the PXP versions on these
SoCs have significant differences.

Use the compatible to configure the ctrl0 register as required dependent
on the platform.
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>