Include bcm2712-rpi-5-b.dtb and overlays/bcm2712d0.dtbo on arm64 RPI boot media. Let firmware select the base tree and apply the D0 overlay by board revision, correcting the D0 debug UART interrupt

Built the arm64 RPI release image. Read-only FAT inspection confirmed
bcm2712-rpi-5-b.dtb and overlays/bcm2712d0.dtbo, both already provided
by the rpi-firmware package.

Tested on one Raspberry Pi 5 Model B 8GB (BCM2712 D0, revision code
0xd04171), with the companion SDHCI, vcbus and framebuffer changes,
the firmware config change D61534, and clock fix D61378. Firmware
selected the base DTB and loaded the D0 overlay automatically. FreeBSD
booted from SD through interactive UART login, with console output on
an HDMI monitor. Hardware validation was limited to this board.

Related reviews:

• https://reviews.freebsd.org/D61534
• https://reviews.freebsd.org/D61378