Fusee stage 2: Fix up loader (no stage 3!). Skeleton chainload behavior.

fusee/fusee-secondary/src/nxboot.c

@@ -0,0 +1,7 @@
+#include "utils.h"
+#include "nxboot.h"
+
+/* This is the main function responsible for booting Horizon. */
+void nxboot_main(void) {
+    /* TODO: Implement this function. */
+}