net/bnx2x: handle guest VLAN for SR-IOV

net/bnx2x: handle guest VLAN for SR-IOV

In case of bnx2xvf pmd, tx packets can support vland id in 2 ways:
1. Setting the mbuf ol_flags=PKT_TX_VLAN_PKT and passing the
vlanid in mbuf->vlan_tci.
2. The tx packet itself has the vlan id included in the packet.
The first case is working as expected but the second case where
the vlan id is included in thetx packets itself was found not
working as expected. To handle that we need to properly set the
start_bd bitfield and the vlan_or_ethertype instead of setting it
to just the ethertype in case of VF.

Signed-off-by: Souvik Dey <sodey@rbbn.com>
Acked-by: Rasesh Mody <rmody@marvell.com>