tg3: shows HW time stamping support only if ptp_capable is present

Current tg3 shows hardware timestamping support for all devices
when that is true only for the hardware with PTP_CAPABLE flag
present.
Signed-off-by: Flavio Leitner <fbl@redhat.com>
Acked-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/tg3.c

@@ -5992,10 +5992,13 @@ static int tg3_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info)
 
 	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
 				SOF_TIMESTAMPING_RX_SOFTWARE |
-				SOF_TIMESTAMPING_SOFTWARE    |
-				SOF_TIMESTAMPING_TX_HARDWARE |
+				SOF_TIMESTAMPING_SOFTWARE;
+
+	if (tg3_flag(tp, PTP_CAPABLE)) {
+		info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE |
 					SOF_TIMESTAMPING_RX_HARDWARE |
 					SOF_TIMESTAMPING_RAW_HARDWARE;
+	}
 
 	if (tp->ptp_clock)
 		info->phc_index = ptp_clock_index(tp->ptp_clock);