Undo aic7xxx changes

I today compiled 2.4.21-rc2 smp with aic79xx-linux-2.4-20030502-tar.gz and discovered no problems or hangs. (Tyan-S2665 with AIC-7902)

I haven't had any problems with the driver since I got this motherboard starting with aic79xx-linux-2.4-20030318-tar.gz and linux-2.4.21-pre5.

Regards Klaus