GSDX: Mask off high bits of calculated GS memory addresses, untested but probably what happens with real hardware.  Fixes crash/memory corruption on starting Fatal Fury Battle Archives Volume 2, hopefully some other games too.

git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5547 96395faa-99c1-11dd-bbfe-3dabce05a288