Update shell.c

To enhance the robustness of key recognition and solve the problem of errors and omissions caused by the lag of state assignment statement
增强方向键识别的鲁棒性，解决状态赋值语句滞后带来的错漏问题

Author: LTreeshu

components/finsh/shell.c

@@ -535,7 +535,7 @@ static void finsh_thread_entry(void *parameter)
         }
         else if (shell->stat == WAIT_SPEC_KEY)
         {
-            if (ch == 0x5b)
+            if (ch == 0x5b || ch == 0x41 || ch == 0x42 || ch == 0x43 || ch == 0x44)
             {
                 shell->stat = WAIT_FUNC_KEY;
                 continue;