Fix bugs when memory size is 0x04C00000/etc.

Was experimenting with trying to match my non-phat's ram size, and realized this could be causing issues with some remasters depending on their settings.

Also removed g_RemasterMode from the ram checks since it won't change the outcome (it might just make the invalid address errors slower, which I don't care about), and it made it easier to test the change.

Not actually tested with any remasters.

-[Unknown]