arm64: dts: Add support for Raspberry Pi Compute Module 4 IO Board

arm64: dts: Add support for Raspberry Pi Compute Module 4 IO Board

It was introduced in mainline during the v5.16 release cycle. Since
many broadcom includes were reworked since v5.10, adding support would
involve more than cherry-picking a DTS addition that uses a few
includes.

To avoid side effects on other models, introduce a DTS that leverages
some existing includes (bcm2711.dtsi and bcm283x-rpi-usb-host.dtsi)
and describes the rest without re-using parts of the Raspberry Pi 4 B
model.

To avoid phandle rotation (0x16, 0x17, and 0x18) across 3 nodes
(dma@7e007000, i2c@7e205000, and interrupt-controller@7ef00100), and the
related changes in other nodes referencing them, hardcode 0x16 as the
phandle for interrupt-controller@7ef00100. This leads to an empty dtdiff
between this new DTB and the one produced by a v5.16-rc8 build.

Authored-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Cyril Brulebois <cyril@debamax.com>
Gbp-Pq: Topic features/arm64
Gbp-Pq: Name arm64-dts-raspberry-Add-support-for-the-CM4.patch