[WIP] DSP: some changes for ARAM ops in wii mode

* The Wii has no ARAM. DMA'ing to/from it via the interface in the DSP MMIO registers doesn't do anything.
* Bump up the ARAM DMA chunk granularity to 32 bytes.
* Stop doing unnecessary byteswaps.
* Remove some special casing when DSP is reading from memory in Wii mode.
* Mask of main memory addrs to turn standard (BAT) mapping addrs into physical memory addrs.
* Make sure all ARAM/RAM/Size parameters are aligned to 32 bytes.
In wii mode writes from the DSP through the accelerator (I'm presuming that's what this function is for) will only work for MEM2, attempting to write to MEM1 does nothing.