Watch for consistently high flips, not spurts

Gets rid of flickering in #3422 while using non-buffered rendering.

Since this function doesn't do these things on an actual PSP, reducing how often this hack is applied should improve things.  Now it watches for more than 30 flips in a row that are too close to each other.  If they start spacing out, it eases off and back on.

This should hopefully be more compatible, and still works for God of War (demo, at least.)

-[Unknown]