Some scePower callback fixes

I did this a while ago and was worried it'd break things.  Never got around to testing it and finally did, everything seems fine (my games at least.)  Also it passes the power/power test.

There's a ton of other scePower funcs but wanted to just get callbacks right at least.  Could fix some game, although I can't see why you'd need to use all those callback slots.

-[Unknown]