UPSTREAM: wifi: ath12k: Fix wrong P2P device link id issue

Wrong P2P device link id value of 0 was introduced in ath12k_mac_op_tx() by [1].

During the P2P negotiation process, there is only one scan vdev with link ID 15.
Currently, the device link ID is incorrectly set to 0 in ath12k_mac_op_tx()
during the P2P negotiation process, which leads to TX failures.

Set the correct P2P device link ID to 15 to fix the TX failure issue.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3

Fixes: 648a121 ("wifi: ath12k: ath12k_mac_op_tx(): MLO support") # [1]
Signed-off-by: Yingying Tang <yingying.tang@oss.qualcomm.com>
Link: https://lore.kernel.org/linux-wireless/20260113054636.2620035-1-yingying.tang@oss.qualcomm.com/

Author: MilanoPipo

drivers/net/wireless/ath/ath12k/wifi7/hw.c

@@ -806,7 +806,10 @@ static void ath12k_wifi7_mac_op_tx(struct ieee80211_hw *hw,
 			return;
 		}
 	} else {
-		link_id = 0;
+		if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
+			link_id = ATH12K_FIRST_SCAN_LINK;
+		else
+			link_id = 0;
 	}
 
 	arvif = rcu_dereference(ahvif->link[link_id]);