Dove clock support

[Andrew Lunn]

> > When moving from kirkwoods old clock management to the generic clock
> > framework, i kept the functionality the same. The old code would turn
> > the PHYs off, but have no way to turn them back on again. The new code
> > is the same.
> 
> No, not exactly the same. In the old code, it was sufficient to call
> the respective kirkwood_..._init function to keep the clock and the
> PHY alive. Now, the respective driver needs to enable the clock in
> order to prevent that the clock and the PHY are shut down. 

Ah yes, you are right.

I must admit, i never thought much about systems using kernel modules.
My experience so far, is that systems using kirkwood tend to have
nearly all drivers built in. The exception seems to be wifi, IPv6, and
all plug+play drivers for USB.

However, now i start thinking about it, with the move to one kernel
per ARM architectures, we are probably going to have more and more
systems using modules, since for example it makes little sense to have
the sata_mv driver built in, when run on an AT91 system...

    Andrew