locking/local_lock: Introduce guard definition for local_lock.

Introduce lock guard definition for local_lock_t. There are no users
yet.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20240620132727.660738-2-bigeasy@linutronix.de


Signed-off-by: Jakub Kicinski <kuba@kernel.org>