mbuf: rename deprecated VLAN flags

mbuf: rename deprecated VLAN flags

PKT_RX_VLAN_PKT and PKT_RX_QINQ_PKT are deprecated for a while.
As explained in [1], these flags were kept to let the applications and
PMDs move to the new flag. There is also a need to support Rx vlan
offload without vlan strip (at least for the ixgbe driver).

This patch renames the old flags for this feature, knowing that some
PMDs were using PKT_RX_VLAN_PKT and PKT_RX_QINQ_PKT to indicate that
the vlan tci has been saved in the mbuf structure.

It is likely that some PMDs do not set the proper flags when doing vlan
offload, and it would be worth making a pass on all of them.

Link: [1] http://dpdk.org/ml/archives/dev/2017-June/067712.html

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>