[Feature] N64 DD BIOS Switching

[0x90shell]

After troubleshooting the ability to boot N64 DD disks from the RetroArch core, I realized that all JPN DD Disks would boot perfectly with the rom.z64 + rom.z64.ndd method using the JPN 1.2 BIOS. This included the translation patched Disks. The one exception to this was the F-Zero X translation which must use the USA released F-Zero X cart, with the US BIOS, to properly render a full translation. A core option to specify BIOS or automated detection of BIOS region would save a lot of headache for future users stumbling across this issue.

I understand this is a low or no priority feature, but I wanted to at least have it documented somewhere for future users who encounter this outlier situation.

Thanks for all your efforts!