feat: added cross compiler and moved headers to include dir

kernel/libk/libk.c

@@ -5,7 +5,7 @@
 #include <stdbool.h>
 #include <libk/kprint.h>
 #include <attributes.h>
-#include "libk.h"
+#include <libk/libk.h>
 
 bool k_addr_in_kspace(void* addr) {
     return addr > kernel_start && addr < kernel_end;