net/hinic: fix MTU consistency with firmware

net/hinic: fix MTU consistency with firmware

The configuration of MTU is inconsistent in the driver and
firmware when the port is stopped, started and reconfigured.
Before, HINIC_MAX_JUMBO_FRAME_SIZE include VLAN tag, but when
frame and pktlen are converted to each other do not include
VLAN tag. And port_mtu_set function will use HINIC_MAX_JUMBO_FRAME_SIZE
to calculate eth_overhead, so MTU will be inconsistent in the driver and
firmware.

Fixes: e542ab51ab27 ("net/hinic: fix jumbo frame flag condition for MTU set")
Cc: stable@dpdk.org
Signed-off-by: Guoyang Zhou <zhouguoyang@huawei.com>