arm: rpi: Sync rpi dts files from Linux

Sync these files, obtained from Linux v5.15.

This adds a devicetree file for rpi_4 which was not there before.

Testing shows no change so far as I can see:
- boots to U-Boot prompt on rpi0, rpi2
- boots to distro on rpi3
- boots to distro on rpi4

I am assuming that syncing with Linux is safe, but the maintainer should
know for sure.

Signed-off-by: Simon Glass <sjg@chromium.org>