net: mscc: ocelot: correctly report the timestamping RX filters in ethtool

The driver doesn't support RX timestamping for non-PTP packets, but it
declares that it does. Restrict the reported RX filters to PTP v2 over
L2 and over L4.

Fixes: 4e3b0468 ("net: mscc: PTP Hardware Clock (PHC) support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mscc/ocelot.c

@@ -1677,7 +1677,10 @@ int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 				 SOF_TIMESTAMPING_RAW_HARDWARE;
 	info->tx_types = BIT(HWTSTAMP_TX_OFF) | BIT(HWTSTAMP_TX_ON) |
 			 BIT(HWTSTAMP_TX_ONESTEP_SYNC);
-	info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) | BIT(HWTSTAMP_FILTER_ALL);
+	info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
+			   BIT(HWTSTAMP_FILTER_PTP_V2_EVENT) |
+			   BIT(HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
+			   BIT(HWTSTAMP_FILTER_PTP_V2_L4_EVENT);
 
 	return 0;
 }