Seed badrand with an rtc read xored with itself (its called BADrand for a reason)

kern/start.c

@@ -1,3 +1,4 @@
+#include "badrand.h"
 #include <assert.h>
 #include <banner.h>
 #include <buddy.h>
@@ -45,6 +46,7 @@ void start() {
         memory_sweep(heap_start, heap_end);
         buddy_init(heap_start, heap_end);
         spinlock_init(&sl);
+        sbadrand(rtc_read_time() ^ swap64(rtc_read_time()));
         for (int i = 0; i < banner_len; i++) uart_putc(banner[i]);
         __sync_synchronize();
         hold = 0;