mailbox: msm_qmp: remove IRQF_NO_SUSPEND while requesting irq

Using IRQF_NO_SUSPEND and enable_irq_wake together can sometime
cause issue in wakeup from suspend and local host may not come
out of suspend on receiving qmp interrupt.

It is sufficient to use enable_irq_wake to mark irq as wakeup
capable.

Change-Id: I714724b31b92d23df0ac6a648f70416a130c9896
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>