Recognize BCM2712 and use the BCM2838 legacy SDRAM alias for firmware-facing address translation, avoiding an unsupported-SoC panic.
This does not translate BCM2712 on-SoC peripheral addresses.

Tested on one Raspberry Pi 5 Model B 8GB (BCM2712 D0, revision code 0xd04171), with firmware configuration D61534, release image change D61535, SDHCI support D61541, clock fix D61378, and the companion framebuffer guard.

Built arm64 GENERIC kernel/modules and the RPI release image.
FreeBSD booted through interactive UART login, with console output on an HDMI monitor. No unsupported-SoC translation panic occurred.
This validates the integrated boot path, rather than every address translation or peripheral DMA path.

Hardware validation was limited to this board.

Related reviews:

• https://reviews.freebsd.org/D61534
• https://reviews.freebsd.org/D61535
• https://reviews.freebsd.org/D61541
• https://reviews.freebsd.org/D61378