Fixing audio glitches with wave and noise channels

lib/ppu.c

@@ -16,6 +16,7 @@ void ppu_init() {
     ctx.current_frame = 0;
     ctx.line_ticks = 0;
     ctx.video_buffer = malloc(YRES * XRES * sizeof(u32));
+    ctx.target_frame_time = 1000/60;
 
     ctx.pfc.line_x = 0;
     ctx.pfc.pushed_x = 0;