I've just turned on SBus burst mode for QLogic cards. I've tested it on a
sun4m and also on sun4c (ss2)- although it isn't really supported on sun4c
because, for differential at leats, it draws too much power for an SS1 or SS2
power supply.

I'm going to commit the changes for 1.5. Can folks make sure they try it in
case it breaks for some wierd reason? The performance boost is substantial
otherwise.

-matt