745x coherency fix for 2.4?

[Benjamin Herrenschmidt]

> The cputable.c change adds CPU_FTR_NEED_COHERENT to all CPUs when
> CONFIG_SMP is set. That's why the changes from #ifdef CONFIG_SMP
> to checking this feature flag work for both SMP and 745x.
> 
> The logic is straight from the 2.6 kernel; I only adapted it where
> the 2.4 kernel was different, like some of the cputable entries
> were missing in 2.4.

Ok, good then. I'll CC to Marcelo

Ben.