core: change types from uint32_t to u32 (e.g)

src/memory/frame.c

@@ -34,7 +34,7 @@ int free_frame(void *frame_ptr)
 	              frame_ptr >= it->addr + it->total_frames * PAGE_SIZE))
 		it = it->next;
 
-	uint32_t index = ((frame_ptr - it->addr) / PAGE_SIZE);
+	u32 index = ((frame_ptr - it->addr) / PAGE_SIZE);
 	SET_FRAME(it->frame_table, index, 0);
 	if (it->first_free_frame > index)
 		it->first_free_frame = index;