port: begin implementing audio

mixer taken from sm64-port and modified to fit PD's naudio thing

MP3 playback not supported yet

audio buffering sucks

src/include/lib/audiomgr.h

@@ -16,4 +16,8 @@ void amgrStartThread(void);
 OSMesgQueue *amgrGetFrameMesgQueue(void);
 void amgrStopThread(void);
 
+#ifndef PLATFORM_N64
+void amgrFrame(void);
+#endif
+
 #endif

src/include/types.h

@@ -3436,17 +3436,29 @@ struct surfacetype {
 union soundnumhack {
 	s16 packed;
 
+#ifdef PLATFORM_BIG_ENDIAN
 	struct {
 		u16 hasconfig : 1;
 		u16 confignum : 15;
 	};
-
 	struct {
 		u16 hasconfig2 : 1;
 		u16 unk02 : 2;
 		u16 mp3priority : 2;
 		u16 id : 11;
 	};
+#else
+	struct {
+		u16 confignum : 15;
+		u16 hasconfig : 1;
+	};
+	struct {
+		u16 id : 11;
+		u16 mp3priority : 2;
+		u16 unk02 : 2;
+		u16 hasconfig2 : 1;
+	};
+#endif
 };
 
 struct audiorussmapping {