arm64: dts: broadcom: Add board DTS for Rpi5 which includes RP1 node

arm64: dts: broadcom: Add board DTS for Rpi5 which includes RP1 node

Add the fully populated DTS for RaspberryPi 5 which includes
the RP1 node definition. The inclusion tree is as follow (the
arrow points to the includer):

rp1-common.dtsi ----> rp1-nexus.dtsi ----> bcm2712-rpi-5-b.dts
                                               ^
                                               |
                                           bcm2712-rpi-5-b-ovl-rp1.dts

This is designed to maximize the compatibility with downstream DT
while ensuring that a fully defined DT (one which includes the RP1
node as opposed to load it from overlay at runtime) is present
since early boot stage.

Since the preferred board DT is the fully populated one, name it
bcm2712-rpi-5-b.dts and move the previous one into
bcm2712-rpi-5-b-ovl-rp1.dts.

Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Link: https://lore.kernel.org/r/20250529135052.28398-9-andrea.porta@suse.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>