ARM: dts: imx6q-utilite-pro: enable 2nd display pipeline

Apart from the already enabled Designware HDMI port, the Utilite Pro
has a second display pipeline which has the following shape:

  IPU1 DI0 --> Parallel display --> tfp410 rgb24 to DVI encoder
                                --> HDMI connector.
Enable support for it.

In addition, since this pipeline is hardwired to IPU1, sever the link
between IPU1 and the SoC-internal Designware HDMI encoder forcing the
latter to be connected to IPU2 instead of IPU1. Otherwise, it is not
possible to drive both displays at high resolution due to the bandwidth
limitations of a single IPU.

Signed-off-by: Christopher Spinrath <christopher.spinrath@rwth-aachen.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>