arm64: dts: broadcom: Add firmware clocks and power nodes to Pi5 DT

arm64: dts: broadcom: Add firmware clocks and power nodes to Pi5 DT

BCM2712 still uses the firmware clocks and power drivers, so add
them to the base device tree.

The brcm,bcm2836-l1-intc controller isn't used on this platform.
It is used on 32-bit kernels for the smp_boot_secondary hook, but
BCM2712 can't run a 32-bit kernel.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20241025-drm-vc4-2712-support-v2-34-35efa83c8fc0@raspberrypi.com
Link: https://lore.kernel.org/r/20241212-dt-bcm2712-fixes-v3-7-44a7f3390331@raspberrypi.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>