net/hns3: fix PTP interrupt logging

net/hns3: fix PTP interrupt logging

PMD driver will receive a PTP interrupt when receive a PTP packet.
But driver doesn't distinguish it. As a result, many unknown events
are printed when many PTP packets are received on the link. The PTP
interrupt is normal, so this patch doesn't log and ignores it.

Fixes: 38b539d96eb6 ("net/hns3: support IEEE 1588 PTP")
Cc: stable@dpdk.org
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>