ARM: dts: update bcm2711-rpi-cm4.dts and -400

Neither CM4 nor Pi 400 have appeared upstream yet, and as a result
they have missed out on improvements to the Pi 4B platform.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

ARM: dts: Bring bcm2711-rpi-400.dts up-to-date

Pi 400 support has not appeared upstream yet, and as a result it has
missed out on improvements to the other Pi 4 platforms.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>