tinker with Xscale performance, anti-log spamming is now only for debug_level...

tinker with Xscale performance, anti-log spamming is now only for debug_level 3 or more. Otherwise polling is done continously for 1 second.

git-svn-id: svn://svn.berlios.de/openocd/trunk@937 b42882b7-edfa-0310-969c-e2dbd0fdcd60