MMIO: Add a NOP write handler type
MMIO: Make invalid handlers a simple specialization of the complex type
MMIO: Pass the read address to read/write handlers and forward it to the complex handlers.
MMIO: Rename Complex to Complex{Read,Write} because MSVC and old GCC are too stupid to figure out overloads
MMIO: Port the DSP/ARAM/AI MMIOs to the new interface.
MMIO: Port the DI MMIOs to the new interface.
MMIO: Port the SI MMIOs to the new interface.
MMIO: Port the AI MMIOs to the new interface.
MMIO: Port the IPC MMIOs to the new interface (untested).
MMIO: Port the EXI MMIOs to the new interface.