Make idle_loop a member of ppc_md

[Anton Blanchard]

Hi Michael,

> Currently the idle loop is selected in idle_setup() by consulting 
> systemcfg->platform and with a few ifdefs as well.
> 
> These five patches make idle_loop a member of the ppc_md structure, and moves 
> the selection into the respective platforms' setup_arch().
> 
> I wrote this and then change my mind, and thought we should instead try and 
> reduce the number of different idle loops. But that looks hard, perhaps 
> impossible, so this might be as good as it gets.

Looks good to me. Ive been meaning to fix up our runlatch handling in
the idle loops, so here are a few more patches on top of your series.

The previous two patches I sent out need to be applied also:

[PATCH] ppc64: use c99 initialisers in cputable code
[PATCH] ppc64: Fix runlatch code to work on pseries machines

Anton