powerpc: Starting machine ref405ep fails with "Could not load PowerPC BIOS 'ppc405_rom.bin'"
Not possible to start QEMU, see below. ppc405_rom.bin is missing from QEMU.
$ qemu-system-ppc -M ref405ep qemu-system-ppc: Could not load PowerPC BIOS 'ppc405_rom.bin'
QEMU emulator version 5.2.0