Add support for RVT-R images on retail HW

[GerbilSoft]

RVT-R images use a different master key than retail images, which can be identified by the signature issuer. I added support for RVT-R encryption in a local version of USB Loader GX, so the loader can properly identify the game; however, when the loader starts the cIOS, the cIOS crashes hard, taking down Bluetooth and power button functionality.

I tried to add RVT-R decryption to wiidisc.c in d2x, but that didn't help, either. I'm guessing the signature issuer and/or certificate chain is checked by IOS, and if it doesn't match retail, it crashes. If that's the issue, this needs to be patched out.