Simplify IRQ handling. dpu_irq_map is a huge table consisting of all possible IRQ entries (including a plenty of 'reserved' = not existing IRQs). It is always used to lookup the interrupt index (in the table) and then to use this index to lookup related interrupt register and mask. For the long period of time these indices had 1:1 correspondence to register/mask pairs. SC7280 introduced 'additional' IRQs removing this correpondence. Replace all IRQ lookup with stable irq indices, which correponds directly to the register/bit pair. The dpu_irq_map table is used only for the lookup of the irq index. Changes since RFC: - rebase on top of msm/msm-next to include SC7280 changes.
