qede: Adverstise software timestamp caps when PHC is not available.

When ptp clock is not available for a PF (e.g., higher PFs in NPAR mode),
get-tsinfo() callback should return the software timestamp capabilities
instead of returning the error.

Fixes: 4c55215c ("qede: Add driver support for PTP")
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NMichal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qede/qede_ptp.c

@@ -337,8 +337,14 @@ int qede_ptp_get_ts_info(struct qede_dev *edev, struct ethtool_ts_info *info)
 {
 	struct qede_ptp *ptp = edev->ptp;
 
-	if (!ptp)
-		return -EIO;
+	if (!ptp) {
+		info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
+					SOF_TIMESTAMPING_RX_SOFTWARE |
+					SOF_TIMESTAMPING_SOFTWARE;
+		info->phc_index = -1;
+
+		return 0;
+	}
 
 	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
 				SOF_TIMESTAMPING_RX_SOFTWARE |