dt-bindings: misc: Add device specific bindings for RaspberryPi RP1

dt-bindings: misc: Add device specific bindings for RaspberryPi RP1

The RP1 is a MFD that exposes its peripherals through PCI BARs. This
schema is intended as minimal support for the clock generator and
gpio controller peripherals which are accessible through BAR1.

Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20250529135052.28398-3-andrea.porta@suse.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>