feat: rank drivers at compile time

kernel/fs/mbr.c

@@ -100,10 +100,9 @@ void mbr_read_from_ide(uint8_t ide_drive) {
     free(mbr_data);
 }
 
-BLOCK_DEV_DRIVER(
+BLOCK_DEV_DRIVER(200) = {
         .name = "mbr",
-        .rank = 100,
         .flags.root_only = 1,
         .check_device = mbr_check_device,
         .free_device = NULL, // todo
-);
+};