Don't ignore the low bits of the framebuf pointer

This fixes graphics in Brave Story under softgpu.

Also, it stops seeing "subarea" renders in Brave Story and SAO with this change, because they weren't subareas (and that's why offsetting the y made it render wrong.)  They were just framebuffers with the wrong address.

I'm not 100% sure of this change, it could probably use more testing, maybe still some of the low bits should be ignored?

Also, JPCSP ignores some of the high bits of fbwidth.  JPCSP does not ignore any of the low bits.

-[Unknown]