linux-imx

dt-bindings: fsl-imx-drm: Add DT binding for the Display Processing Unit

This patch adds device tree binding for the Display Processing Unit(DPU),
as found in i.MX8qxp SoC.

The DPU is comprised of two main components that include a blit engine
for 2D graphics accelertations and a display controller for display
output processing, as well as a command sequencer.

Signed-off-by: Liu Ying <victor.liu@nxp.com>