dt-bindings: arm: bcm: Add BCM2712 SoC support

dt-bindings: arm: bcm: Add BCM2712 SoC support

The BCM2712 SoC is found on Raspberry Pi 5. Add compatible string to
acknowledge its new chipset.

Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/cfc4db17981ef946a71d40d522118a560aa0f15b.1717061147.git.andrea.porta@suse.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>