Warning will appear when running P2P GO:

WARNING: suspicious RCU usage
drivers/net/wireless/ath/ath12k/mac.c:583 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/0/0.
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.8.0-rc4-wt-ath+ #4
Call Trace:
 <IRQ>
 dump_stack_lvl+0x82/0xa0
 dump_stack+0x14/0x20
 lockdep_rcu_suspicious+0x214/0x3b0
 ath12k_mac_get_ar_by_vdev_id+0x192/0x220 [ath12k]
 ath12k_wmi_op_rx+0x2d7/0x1b40 [ath12k]

ath12k_mac_get_ar_by_vdev_id() requires its callers to have called
rcu_read_lock(), but in ath12k_wmi_p2p_noa_event() it is called without
doing so, and hence the warning was triggered.

Add rcu_read_lock() and rcu_read_unlock() to avoid warning.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: 9411eecb ("wifi: ath12k: implement handling of P2P NoA event")
Reported-by: Kalle Valo <quic_kvalo@quicinc.com>
Closes: https://lore.kernel.org/linux-wireless/87o7cusyvw.fsf@kernel.org/Signed-off-by: Kang Yang <quic_kangyang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240223054505.438839-1-quic_kangyang@quicinc.com