Fix sound key split tables

[huderlem]

Due to the way mks4agb (Nintendo's tool) works, key split table labels can (and do) appear before the actual start of the key split table data. If you look at the first keysplit table KeySplitTable_8455224, you'll notice there is some non-keysplit data that occurs before the real keysplit table begins. This is because the key split tables don't map instruments for the entire instrument range (0-127)--they only map subsets, and the upper and lower ranges aren't necessarily 0 or 127.

For example if a key split table maps an instrument range of 10-20, then the key split table label will occur 10 bytes before the actual key split data. Therefore, the instruments naturally map to the key split table without any extra offset calculation.

As a result, pokeruby's key split tables currently bleed into each other, and their is voice data bleeding into the first one.