sched/group: move task group into task_tcb_s to improve performance

move task group into task_tcb_s to avoid access allocator to improve performance

for Task Termination, the time consumption will be reduced ~2us (Tricore TC397 300MHZ):
15.97(us) -> 13.55(us)

Signed-off-by: chao an <anchao@lixiang.com>

include/nuttx/mm/map.h

@@ -125,7 +125,7 @@ void mm_map_unlock(void);
  * Name: mm_map_initialize
  *
  * Description:
- *   Initialization function, called only by group_initialize
+ *   Initialization function, called only by group_postinitialize
  *
  * Input Parameters:
  *   mm     - Pointer to the mm_map structure to be initialized

include/nuttx/sched.h

@@ -680,6 +680,10 @@ struct task_tcb_s
 
   struct tcb_s cmn;                      /* Common TCB fields               */
 
+  /* Task Group *************************************************************/
+
+  struct task_group_s group;            /* Pointer to shared task group data */
+
   /* Task Management Fields *************************************************/
 
 #ifdef CONFIG_SCHED_STARTHOOK