-machine raspi4b won't dump dtb

Host environment

• Operating system: Ubuntu 24.04.1 LTS
• OS/kernel version: 6.8.0-51-generic
• Architecture: x86_64
• QEMU flavor: qemu-system-aarch64
• QEMU version: QEMU emulator version 9.2.50 (v9.2.0-319-gca80a5d026)
• QEMU command line: qemu-system-aarch64 -machine raspi4b -machine dumpdtb=p.dmp

Emulated/Virtualized environment

• Operating system: custom
• Architecture: aarch64

Description of problem

the raspi4b machine won't dump tdb

Steps to reproduce

$ qemu-system-aarch64 -machine virt -machine dumpdtb=p.dmp
qemu-system-aarch64: info: dtb dumped to p.dmp. Exiting.
$ qemu-system-aarch64 -machine raspi4b -machine dumpdtb=p.dmp

notice no dtb is dumped for the raspi4b machine

Additional information

see also #2729 (closed)