net: lan969x: fix the use of spin_lock in PTP handler

We are mixing the use of spin_lock() and spin_lock_irqsave() functions
in the PTP handler of lan969x. Fix this by correctly using the _irqsave
variants.

Fixes: 24fe835 ("net: lan969x: add PTP handler function")
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

[1]: https://lore.kernel.org/netdev/20241024-sparx5-lan969x-switch-driver-2-v2-10-a0b5fae88a0f@microchip.com/

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c

@@ -273,9 +273,9 @@ static irqreturn_t lan969x_ptp_irq_handler(int irq, void *args)
 		if (WARN_ON(!skb_match))
 			continue;
 
-		spin_lock(&sparx5->ptp_ts_id_lock);
+		spin_lock_irqsave(&sparx5->ptp_ts_id_lock, flags);
 		sparx5->ptp_skbs--;
-		spin_unlock(&sparx5->ptp_ts_id_lock);
+		spin_unlock_irqrestore(&sparx5->ptp_ts_id_lock, flags);
 
 		/* Get the h/w timestamp */
 		sparx5_get_hwtimestamp(sparx5, &ts, delay);