ARM:OMAP: Add interrupt handling interface in MMU FWK

This adds the entry point in omap mmu framework to handle mmu
interrupt. Users of this framework can use its workqueue interface in
order to accomplish their irq-driven work.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>