arm64: dts: zynqmp: Add power domain for the DisplayPort DMA controller

The DisplayPort DMA controller (DPDMA) is located in the same power
domain as the DisplayPort Subsystem (DPSUB). Specify the power domain in
the device tree.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20210306230915.14979-1-laurent.pinchart@ideasonboard.com


Signed-off-by: Michal Simek <michal.simek@xilinx.com>