Adding send end key as a wake-up source

On MSM chip there are three Interrupt controllers. One for ARM11, one for ARM9 and one dedicated Interrupt controller(Simple Interrupt Controller(SIC), this is always on) to work when both processors sleep. So before ARM11 sleeps we have to send the wake-up irqs to CP. So that MPP IC will monitors only those wake-up interrupts send by AP. This is achieved by using the kernel function enalbe_irq_wake(irq no). This will add the flag IRQ_WAKE to that descriptor of that particular irq. So whenever AP go to sleep it will send this irq number also to the CP as a wake-up soruce.