TEST: Sleep patch #4

[Benjamin Herrenschmidt]

Ok, here's the 4th iteration of the patch. It includes John Steele Scott fixes for
cpufreq and the sound driver and fixes a problem where memory refresh wouldn't properly
be re-enabled on the video chip upon wakeup. I also cleaned a bit more the MDLL reset
code for r300, plus a couple of other things.

http://gate.crashing.org/~benh/albook-ibookg4-sleep-4.diff

Ben.