sched: add spinlock to sched_note_preemption and nxsched_critmon_pree…

[hujun260]

Summary

Add spinlock synchronization to sched_note_preemption and nxsched_critmon_preemption functions. This change ensures thread-safe access to global state during preemption notification and critical section monitoring, preventing race conditions in SMP and interrupt-driven environments.

Changes

Files modified:

• drivers/note/note_driver.c
• sched/sched/sched_critmonitor.c

Key changes:

• Added spinlock protection (g_note_lock) to sched_note_preemption to guard access to the global note driver list and prevent concurrent modifications.
• Introduced a new spinlock (g_crimonitor_lock) in sched_critmonitor.c to protect global state in nxsched_critmon_preemption.
• Wrapped all critical sections in both functions with spin_lock_irqsave_notrace/spin_unlock_irqrestore_notrace.

Synchronization pattern:

irqstate_t flags;
flags = spin_lock_irqsave_notrace(&lock);
// critical section
spin_unlock_irqrestore_notrace(&lock, flags);