ARM: dts: Add Raspberry Pi Compute Module 4 IO Board

This adds the matching carrier for Raspberry Pi Compute Module 4.
Instead of xHCI USB host controller there is just a USB 2.0 interface
connected to the DWC2 controller from the BCM2711. As a result
there is a free PCIe Gen 2 socket. Also there are 2 full-size HDMI 2.0
connectors.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1628334401-6577-10-git-send-email-stefan.wahren@i2se.com


Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org>