The transition time for the 7447A is around 8ms which makes it possible
to use the ondemand governor.  This has been tested on the iBook G4
(PowerBook6,7).
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>