net/bnxt: support for QinQ insertion and stripping

net/bnxt: support for QinQ insertion and stripping

Driver will accelerate only outer/S-VLAN insertion by turning on
the appropriate bits in the Tx Buffer Descriptor when the packet
arrives for transmission.
The TPID to be used for this S-VLAN is conveyed by the vlan_tpid_set
dev_op which will terminate in the driver.
In the Rx path, driver will continue providing the stripped vlan tag
in the mbuf's vlan tci field. This would be the outermost vlan tag
in a double-tagged packet or the vlan tag for a single vlan tagged pkt.

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>