fix msaa detection
Round IR scale down to whole number if using 1.5x/2.5x IR, if game ini specifies -1 for EFBScale.

Fixes issue 6210.
Hastily committing untested code without making sure i didn't miss anything first? I would never!
Someone take my commit rights away.
Adjusted the ARAM DMA transfer size again.  Fixes the audio in the Sonic Mega Collection games.