feat: rewrite existing feature flags

kernel/command.c

@@ -1,6 +1,7 @@
 //
 // Created by rick on 23-02-21.
 //
+#ifdef ENABLE_K_SHELL
 #include <attributes.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -292,7 +293,6 @@ void att_noreturn main_loop(void *data) {
     }
 }
 
-#ifdef K_SHELL
 
 void main_loop_start() {
     task_spawn(main_loop, NULL, "main");