Miscellaneous libultra header fixes (#2139)

* Miscellaneous libultra header fixes

* Fix bss?

* Reword RCP timeout

src/code/graph.c

@@ -179,6 +179,7 @@ void Graph_TaskSet00(GraphicsContext* gfxCtx) {
     {
         CfbInfo* cfb;
 
+        // Schedule a message to be handled in 3 seconds, for RCP timeout
         osSetTimer(&timer, OS_USEC_TO_CYCLES(3000000), 0, &gfxCtx->queue, (OSMesg)666);
 
         osRecvMesg(&gfxCtx->queue, &msg, OS_MESG_BLOCK);