octeontx2-af: Increment ptp refcount before use

Before using the ptp pci device by AF driver increment
the reference count of it.

Fixes: a8b90c9d26 ("octeontx2-af: Add PTP device id for CN10K and 95O silcons")
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/ptp.c

@@ -60,6 +60,8 @@ struct ptp *ptp_get(void)
 	/* Check driver is bound to PTP block */
 	if (!ptp)
 		ptp = ERR_PTR(-EPROBE_DEFER);
+	else
+		pci_dev_get(ptp->pdev);
 
 	return ptp;
 }