Match and split unknown_003260.c into audiomgr.c and audiosfx.c (#364)

* Minor code cleanup and documenting in audio.c

* Match to func_80002DF8 to _amDmaNew

* Match func_800042CC

* Match func_8000410C

* Match func_800041FC as _removeEvents, and rename thread4_main to __amMain while also getting it's code to closer resemble the example code

* Add missing file

* MAtch __clearAudioDMA

* Cleanup __clearAudioDMA to match our code style a little better

* Match __amHandleFrameMsg

* Rename audio microcode from unknown, and clean up some code styles and variables names

* WIP audioNewThread

* Update WIP for audioNewThread

* Close to matching audioNewThread

* Match amCreateAudioMgr

* Match __amDMA

* Add constants, and remove static functions from header

* Make funcitons static where the originals were

* Fix score.py

* Split audiomgr and audiosfx files

* WIP clean up of audiomgr.c

* Finalize split of audiomgr and audiosfx

* Use AMAudioMgr

* Move the deck chairs

* Clean up sfx header

* Cleanup

* Cleanup sfx file, and move asm files

* Update score

* Fix NON_EQUIVALENT

* Match _sndpVoiceHandler

* Update some types

lib/src/os/osAiGetLength.c

@@ -3,6 +3,13 @@
 
 #include "PR/rcp.h"
 
+/**
+ * This function (osAiGetLength) returns the number of bytes remaining in the current DMA buffer.
+ * Notes:
+ * For hardware version 1.0, the audio DMA length register is only 15-bit long and thus supports 
+ * a maximum transfer size of 32 Kbytes. In the final release, this register is extended to 
+ * 18 bits to support a transfer of 256 Kbytes. 
+ */
 u32 osAiGetLength(void) {
     return IO_READ(AI_LEN_REG);
 }