arm64: dts: imx8mp pollux: add displays for expansion board
The same displays that can be connected directly to the
imx8mp-phyboard-pollux can also be connected to the expansion board
PEB-AV-10. For displays connected to the expansion board, a second LVDS
channel of the i.MX 8M Plus SoC is used and only a single display
connected to the SoC LVDS display bridge at a given time is supported.