GIC irq_start detection breaks 3.2 boot on platforms without PPIs

[Russell King - ARM Linux]

On Fri, Nov 25, 2011 at 03:41:57PM +0000, Will Deacon wrote:
> Ok, if you're happy with my logic then I can put the patch into Russell's
> patch system.

I've merged this into my fixes branch, but when I re-merge this with
Marc's irqchip consolidation, I get conflicts.  I think I've fixed it
correctly, but please check the result, which you'll find in my for-next
branch.

Thanks.